Please Help - CIDR - How the bits work [7:75050]
I just started my routing class for my CCNP. We are covering CIDR. The book is VEERY vague on how the bit patterns break down and are used. This was a problem posed in one of my CCNP labs I have network number 192.168.24.0 / 22 from this I need networks with 400 hosts 200 hosts 50 hosts 50 hosts 2 hosts (for serial int - no ip un-numbered allowed ) 2 hosts 2 hosts Also no NATing Thanks all I really could use the help Steve Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75050&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Re: Please Help - CIDR - How the bits work [7:75050]
> I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts 192.168.24.0/23 - 512 (400 hosts fit nicely) 192.168.26.0/24 - 256 (200 hosts fit nicely) 192.168.27.0/26 - 64 (50 hosts -"-) 192.168.27.64/26 - 64 (50 hosts -"-) 192.168.27.128/30 - 4 (I'm assuming /31 is not allowed, also) **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Let me give you a bit of a clue - For the 400 hosts you will need a /23 200 hosts you will need a /24 50 hosts you will need a /26 50 hosts you will need another /26 2 hosts (for serial int - no ip un-numbered allowed )and for these you will need /30s (/32s are possible but probably not what your class requires. If you need more help, please let me know, but try and work it out for yourself first. Best regards, Dom Stocqueler SysDom Technologies Visit our website - www.sysdom.org -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steven Aiello Sent: 09 September 2003 13:02 To: [EMAIL PROTECTED] Subject: Please Help - CIDR - How the bits work [7:75050] I just started my routing class for my CCNP. We are covering CIDR. The book is VEERY vague on how the bit patterns break down and are used. This was a problem posed in one of my CCNP labs I have network number 192.168.24.0 / 22 from this I need networks with 400 hosts 200 hosts 50 hosts 50 hosts 2 hosts (for serial int - no ip un-numbered allowed ) 2 hosts 2 hosts Also no NATing Thanks all I really could use the help Steve **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75064&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Re: Please Help - CIDR - How the bits work [7:75050]
I get the same results as Marko, but this may lay it out so you (and others) can see the development: IP address = 32 bits Network portion = 22 bits Host portion = 10 bits Total addresses for host portion = 2^10 = 1024 Start with 192.168.24.0/22 Focus on the 3rd octet (network_host): 000110_00 400 hosts requires 9 bits (2^8 = 256, 2^9 = 512) and you will have some left in this block divide the /22 into two blocks of 512 addresses each: 0001100_0 (.24/23) and 000_0 (.26/23) use .24/23 for the 400-host network 200 hosts requires 8 bits (2^7 = 128, 2^8 = 256) and there will be some left in this block, too divide the .26/25 into 2 blocks of 256 addresses each: 0000 (.26/24) and 0001 (.27/24) use .26/24 for the 200-host network 50 hosts requires 6 bits (2^5 = 32, 2^6 = 64) and you will again have some leftovers divide the .27/24 into 4 blocks of 64 addresses each now looking at the 4th octet: 00_00 (.0/26), 01_00 (.64/26), 10_00 (.128/26), and 11_00 (.192/26) use the first two for the 50-host networks and the rest is easy My personal rule is to always start with the biggest blocks and work down from there. HTH Annlee Steven Aiello wrote: > I just started my routing class for my CCNP. We are covering CIDR. The > book is VEERY vague on how the bit patterns break down and are used. > > > This was a problem posed in one of my CCNP labs > > I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts > > Also no NATing > > Thanks all I really could use the help > > Steve > **Please support GroupStudy by purchasing from the GroupStudy Store: > http://shop.groupstudy.com > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75069&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
No offense, but this is CCNA material. If you are going for your CCNP, then you should already have your CCNA and know the answer. But anyway... If you need a network with 400 hosts, the smallest subnet would have a /23 mask. So take the first part of your given network and assign it to that: 192.168.24.0/23 (192.168.24.0-192.168.25.255) Then you need one with 200 hosts. Well, that could fit within a /24 subnet, so assign the next available to that: 192.168.26.0/24 (192.168.26.0-192.168.26.255) Now you only have 192.168.27.0/24 left from the original 192.168.24.0/23 (which covered 192.168.24.0-192.168.27.255). You need two 50's, so that should fit within /26 subnets each. Assign them: 192.168.27.0/26 (192.168.27.0-192.168.27.63) 192.168.27.64/26 (192.168.27.64-192.168.27.191) Finally, you need three subnets that can have two hosts each, which would fit within /30 subnets. So assign: 192.168.27.192/30 192.168.27.196/30 192.168.27.200/30 Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Steven Aiello [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 8:02 AM To: [EMAIL PROTECTED] Subject: Please Help - CIDR - How the bits work [7:75050] I just started my routing class for my CCNP. We are covering CIDR. The book is VEERY vague on how the bit patterns break down and are used. This was a problem posed in one of my CCNP labs I have network number 192.168.24.0 / 22 from this I need networks with 400 hosts 200 hosts 50 hosts 50 hosts 2 hosts (for serial int - no ip un-numbered allowed ) 2 hosts 2 hosts Also no NATing Thanks all I really could use the help Steve **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75066&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Here's a great resource: pad http://www.nanog.org/isp.html#cidr scroll down to CIDR and download "Understanding IP Addressing: Everything You Ever Wanted to Know" by Chuck Semeria Looking at your specific problem - think in powers of two. 400 nodes is greater than 256 but less than 512. Use /23 out of your allocation. 200 is less than 256 so use a /24. 50 is greater than 32 and less than 64 so use a /26 for each. The serial links each need a /30. Probably best to take the last /28 from the allocation and break it down into four /30s. > -Original Message- > From: Steven Aiello [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 7:02 AM > To: [EMAIL PROTECTED] > Subject: Please Help - CIDR - How the bits work [7:75050] > > > I just started my routing class for my CCNP. We are covering > CIDR. The > book is VEERY vague on how the bit patterns break down > and are used. > > > This was a problem posed in one of my CCNP labs > > I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts > > Also no NATing > > Thanks all I really could use the help > > Steve Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75070&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Woops, one of the ranges is wrong. Should be 192.168.27.64/26 (192.168.27.64-192.168.27.127) and not: 192.168.27.64/26 (192.168.27.64-192.168.27.191) like I said. Given that you could move all of the latter subnets up, or leave open 192.168.27.128 for another /26 subnet. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Reimer, Fred [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 10:26 AM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] No offense, but this is CCNA material. If you are going for your CCNP, then you should already have your CCNA and know the answer. But anyway... If you need a network with 400 hosts, the smallest subnet would have a /23 mask. So take the first part of your given network and assign it to that: 192.168.24.0/23 (192.168.24.0-192.168.25.255) Then you need one with 200 hosts. Well, that could fit within a /24 subnet, so assign the next available to that: 192.168.26.0/24 (192.168.26.0-192.168.26.255) Now you only have 192.168.27.0/24 left from the original 192.168.24.0/23 (which covered 192.168.24.0-192.168.27.255). You need two 50's, so that should fit within /26 subnets each. Assign them: 192.168.27.0/26 (192.168.27.0-192.168.27.63) 192.168.27.64/26 (192.168.27.64-192.168.27.191) Finally, you need three subnets that can have two hosts each, which would fit within /30 subnets. So assign: 192.168.27.192/30 192.168.27.196/30 192.168.27.200/30 Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Steven Aiello [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 8:02 AM To: [EMAIL PROTECTED] Subject: Please Help - CIDR - How the bits work [7:75050] I just started my routing class for my CCNP. We are covering CIDR. The book is VEERY vague on how the bit patterns break down and are used. This was a problem posed in one of my CCNP labs I have network number 192.168.24.0 / 22 from this I need networks with 400 hosts 200 hosts 50 hosts 50 hosts 2 hosts (for serial int - no ip un-numbered allowed ) 2 hosts 2 hosts Also no NATing Thanks all I really could use the help Steve **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75077&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Reimer, Fred wrote: > > No offense, but this is CCNA material. Do they still teach classful for CCNA, though? Perhaps the only thing that's hard for him is that 192.168.24.0 has a mask of 255.255.255.0 in a classful system. Moving the prefix over to the left of that classful boundary isn't something they teach for CCNA yet. (They will soon. The new Networking Academy books teach it from the start now.) Priscilla > If you are going for > your CCNP, then > you should already have your CCNA and know the answer. But > anyway... > > If you need a network with 400 hosts, the smallest subnet would > have a /23 > mask. So take the first part of your given network and assign > it to that: > > 192.168.24.0/23 (192.168.24.0-192.168.25.255) > > Then you need one with 200 hosts. Well, that could fit within > a /24 subnet, > so assign the next available to that: > > 192.168.26.0/24 (192.168.26.0-192.168.26.255) > > Now you only have 192.168.27.0/24 left from the original > 192.168.24.0/23 > (which covered 192.168.24.0-192.168.27.255). You need two > 50's, so that > should fit within /26 subnets each. Assign them: > > 192.168.27.0/26 (192.168.27.0-192.168.27.63) > 192.168.27.64/26 (192.168.27.64-192.168.27.191) > > Finally, you need three subnets that can have two hosts each, > which would > fit within /30 subnets. So assign: > > 192.168.27.192/30 > 192.168.27.196/30 > 192.168.27.200/30 > > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA > 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary > information which > may be legally privileged. It is intended only for the named > recipient(s). > If an addressing or transmission error has misdirected the > email, please > notify the author by replying to this message. If you are not > the named > recipient, you are not authorized to use, disclose, distribute, > copy, print > or rely on this email, and should immediately delete it from > your computer. > > > -Original Message- > From: Steven Aiello [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 8:02 AM > To: [EMAIL PROTECTED] > Subject: Please Help - CIDR - How the bits work [7:75050] > > I just started my routing class for my CCNP. We are covering > CIDR. The > book is VEERY vague on how the bit patterns break down and > are used. > > > This was a problem posed in one of my CCNP labs > > I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts > > Also no NATing > > Thanks all I really could use the help > > Steve > **Please support GroupStudy by purchasing from the GroupStudy > Store: > http://shop.groupstudy.com > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75080&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
May be I had advanced access to the new NA material then ;-) In my view, a NA should be able to handle basic RIP, OSPF, EIGRP in a small to medium sized network. That would certainly include CIDR. A NP, IMO, would be for advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a mid-large sized network for connection to the Internet including minimal BGP. IE, IMO, is for ISP engineers that have to deal with extensive IS-IS, BGP using all options, etc, and large to huge (global) networks. May be I'm just expecting too much, but if you don't understand CIDR you shouldn't be allowed anywhere near a router, let alone be responsible for configuring them. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 12:33 PM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] Reimer, Fred wrote: > > No offense, but this is CCNA material. Do they still teach classful for CCNA, though? Perhaps the only thing that's hard for him is that 192.168.24.0 has a mask of 255.255.255.0 in a classful system. Moving the prefix over to the left of that classful boundary isn't something they teach for CCNA yet. (They will soon. The new Networking Academy books teach it from the start now.) Priscilla > If you are going for > your CCNP, then > you should already have your CCNA and know the answer. But > anyway... > > If you need a network with 400 hosts, the smallest subnet would > have a /23 > mask. So take the first part of your given network and assign > it to that: > > 192.168.24.0/23 (192.168.24.0-192.168.25.255) > > Then you need one with 200 hosts. Well, that could fit within > a /24 subnet, > so assign the next available to that: > > 192.168.26.0/24 (192.168.26.0-192.168.26.255) > > Now you only have 192.168.27.0/24 left from the original > 192.168.24.0/23 > (which covered 192.168.24.0-192.168.27.255). You need two > 50's, so that > should fit within /26 subnets each. Assign them: > > 192.168.27.0/26 (192.168.27.0-192.168.27.63) > 192.168.27.64/26 (192.168.27.64-192.168.27.191) > > Finally, you need three subnets that can have two hosts each, > which would > fit within /30 subnets. So assign: > > 192.168.27.192/30 > 192.168.27.196/30 > 192.168.27.200/30 > > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA > 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary > information which > may be legally privileged. It is intended only for the named > recipient(s). > If an addressing or transmission error has misdirected the > email, please > notify the author by replying to this message. If you are not > the named > recipient, you are not authorized to use, disclose, distribute, > copy, print > or rely on this email, and should immediately delete it from > your computer. > > > -Original Message- > From: Steven Aiello [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 8:02 AM > To: [EMAIL PROTECTED] > Subject: Please Help - CIDR - How the bits work [7:75050] > > I just started my routing class for my CCNP. We are covering > CIDR. The > book is VEERY vague on how the bit patterns break down and > are used. > > > This was a problem posed in one of my CCNP labs > > I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts > > Also no NATing > > Thanks all I really could use the help > > Steve > **Please support GroupStudy by purchasing from the GroupStudy > Store: > http://shop.groupstudy.com > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75092&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Re: Please Help - CIDR - How the bits work [7:75050]
""Reimer, Fred"" wrote in message news:[EMAIL PROTECTED] > May be I had advanced access to the new NA material then ;-) In my view, a > NA should be able to handle basic RIP, OSPF, EIGRP in a small to medium > sized network. That would certainly include CIDR. A NP, IMO, would be for > advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a mid-large > sized network for connection to the Internet including minimal BGP. IE, > IMO, is for ISP engineers that have to deal with extensive IS-IS, BGP using > all options, etc, and large to huge (global) networks. > > May be I'm just expecting too much, but if you don't understand CIDR you > shouldn't be allowed anywhere near a router, let alone be responsible for > configuring them. with all due respect, I disagree. CCNA is promoted by Cisco as being someone capable of designing and configuring a small network. http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certification_type_home.html "The CCNA certification (Cisco Certified Network Associate) indicates a foundation in and apprentice knowledge of networking. CCNA certified professionals can install, configure, and operate LAN, WAN, and dial access services for small networks (100 nodes or fewer), including but not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists." my experience has been that small nets have less if any need for CIDR knowledge or expertise. Cisco has over the past couple of years been slowly upping the ante, and I wish Cisco would get clear as to what skill sets are appropriate at what certification level. Cisco tends to be all over the map on this, and has been the netire time I have been playing at certification. But in general, I believe the idea is that CCxA is beginner, CCxP is intermediate, and CCIE is high level. as with all things certification related, YMMV. I've known CCNA's who manage large networks, and I've known CCIE's whose knowledge of certain specific areas was less than expert. As can be expected, depending on experience, job, place of employment, years in the field, etc. Chuck > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary information which > may be legally privileged. It is intended only for the named recipient(s). > If an addressing or transmission error has misdirected the email, please > notify the author by replying to this message. If you are not the named > recipient, you are not authorized to use, disclose, distribute, copy, print > or rely on this email, and should immediately delete it from your computer. > > > -Original Message----- > From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 12:33 PM > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > Reimer, Fred wrote: > > > > No offense, but this is CCNA material. > > Do they still teach classful for CCNA, though? Perhaps the only thing that's > hard for him is that 192.168.24.0 has a mask of 255.255.255.0 in a classful > system. Moving the prefix over to the left of that classful boundary isn't > something they teach for CCNA yet. (They will soon. The new Networking > Academy books teach it from the start now.) > > Priscilla > > > If you are going for > > your CCNP, then > > you should already have your CCNA and know the answer. But > > anyway... > > > > If you need a network with 400 hosts, the smallest subnet would > > have a /23 > > mask. So take the first part of your given network and assign > > it to that: > > > > 192.168.24.0/23 (192.168.24.0-192.168.25.255) > > > > Then you need one with 200 hosts. Well, that could fit within > > a /24 subnet, > > so assign the next available to that: > > > > 192.168.26.0/24 (192.168.26.0-192.168.26.255) > > > > Now you only have 192.168.27.0/24 left from the original > > 192.168.24.0/23 > > (which covered 192.168.24.0-192.168.27.255). You need two > > 50's, so that > > should fit within /26 subnets each. Assign them: > > > > 192.168.27.0/26 (192.168.27.0-192.168.27.63) > > 192.168.27.64/26 (192.168.27.64-192.168.27.191) > > > > Finally, you need three subnets that can have two hosts each, > > which would > > fit within /30 subnets. So assign: > > > > 192.168.27.192/30 > > 192.168.27.196/30 > > 192.168.27.200/30 > > > > > > Fred Reimer - CCNA > > > > > > Eclipsy
Re: Please Help - CIDR - How the bits work [7:75050]
We are now teaching VLSM/CIDR in the CCNA curriculum. Prof. Tom Lisa, CCAI Community College of Southern Nevada Cisco ATC/Regional Networking Academy "Cunctando restituit rem" Priscilla Oppenheimer wrote: Reimer, Fred wrote: > > No offense, but this is CCNA material. Do they still teach classful for CCNA, though? Perhaps the only thing that's hard for him is that 192.168.24.0 has a mask of 255.255.255.0 in a classful system. Moving the prefix over to the left of that classful boundary isn't something they teach for CCNA yet. (They will soon. The new Networking Academy books teach it from the start now.) Priscilla > If you are going for > your CCNP, then > you should already have your CCNA and know the answer. But > anyway... > > If you need a network with 400 hosts, the smallest subnet would > have a /23 > mask. So take the first part of your given network and assign > it to that: > > 192.168.24.0/23 (192.168.24.0-192.168.25.255) > > Then you need one with 200 hosts. Well, that could fit within > a /24 subnet, > so assign the next available to that: > > 192.168.26.0/24 (192.168.26.0-192.168.26.255) > > Now you only have 192.168.27.0/24 left from the original > 192.168.24.0/23 > (which covered 192.168.24.0-192.168.27.255). You need two > 50's, so that > should fit within /26 subnets each. Assign them: > > 192.168.27.0/26 (192.168.27.0-192.168.27.63) > 192.168.27.64/26 (192.168.27.64-192.168.27.191) > > Finally, you need three subnets that can have two hosts each, > which would > fit within /30 subnets. So assign: > > 192.168.27.192/30 > 192.168.27.196/30 > 192.168.27.200/30 > > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA > 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary > information which > may be legally privileged. It is intended only for the named > recipient(s). > If an addressing or transmission error has misdirected the > email, please > notify the author by replying to this message. If you are not > the named > recipient, you are not authorized to use, disclose, distribute, > copy, print > or rely on this email, and should immediately delete it from > your computer. > > > -Original Message- > From: Steven Aiello [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 8:02 AM > To: [EMAIL PROTECTED] > Subject: Please Help - CIDR - How the bits work [7:75050] > > I just started my routing class for my CCNP. We are covering > CIDR. The > book is VEERY vague on how the bit patterns break down and > are used. > > > This was a problem posed in one of my CCNP labs > > I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts > > Also no NATing > > Thanks all I really could use the help > > Steve > **Please support GroupStudy by purchasing from the GroupStudy > Store: > http://shop.groupstudy.com > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75118&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
I guess my expectation and Cisco's, or at least their current expectations as listed on their web site, don't match then. By my definition a beginner should know about CIDR, EIGRP, and OSPF. It's not like they are inherently difficult to understand. People tend to make it sound like rocket science or voodoo magic. It's just a routing protocol folks. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: "Chuck Whose Road is Ever Shorter" [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 3:56 PM To: [EMAIL PROTECTED] Subject: Re: Please Help - CIDR - How the bits work [7:75050] ""Reimer, Fred"" wrote in message news:[EMAIL PROTECTED] > May be I had advanced access to the new NA material then ;-) In my view, a > NA should be able to handle basic RIP, OSPF, EIGRP in a small to medium > sized network. That would certainly include CIDR. A NP, IMO, would be for > advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a mid-large > sized network for connection to the Internet including minimal BGP. IE, > IMO, is for ISP engineers that have to deal with extensive IS-IS, BGP using > all options, etc, and large to huge (global) networks. > > May be I'm just expecting too much, but if you don't understand CIDR you > shouldn't be allowed anywhere near a router, let alone be responsible for > configuring them. with all due respect, I disagree. CCNA is promoted by Cisco as being someone capable of designing and configuring a small network. http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certification_t ype_home.html "The CCNA certification (Cisco Certified Network Associate) indicates a foundation in and apprentice knowledge of networking. CCNA certified professionals can install, configure, and operate LAN, WAN, and dial access services for small networks (100 nodes or fewer), including but not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists." my experience has been that small nets have less if any need for CIDR knowledge or expertise. Cisco has over the past couple of years been slowly upping the ante, and I wish Cisco would get clear as to what skill sets are appropriate at what certification level. Cisco tends to be all over the map on this, and has been the netire time I have been playing at certification. But in general, I believe the idea is that CCxA is beginner, CCxP is intermediate, and CCIE is high level. as with all things certification related, YMMV. I've known CCNA's who manage large networks, and I've known CCIE's whose knowledge of certain specific areas was less than expert. As can be expected, depending on experience, job, place of employment, years in the field, etc. Chuck > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary information which > may be legally privileged. It is intended only for the named recipient(s). > If an addressing or transmission error has misdirected the email, please > notify the author by replying to this message. If you are not the named > recipient, you are not authorized to use, disclose, distribute, copy, print > or rely on this email, and should immediately delete it from your computer. > > > -----Original Message- > From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 12:33 PM > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > Reimer, Fred wrote: > > > > No offense, but this is CCNA material. > > Do they still teach classful for CCNA, though? Perhaps the only thing that's > hard for him is that 192.168.24.0 has a mask of 255.255.255.0 in a classful > system. Moving the prefix over to the left of that classful boundary isn't > something they teach for CCNA yet. (They will soon. The new Networking > Academy books teach it from the start now.) > > Priscilla > > > If you are going for > > your CCNP, then > > you should already have your CCNA and know the answer. But > > anyway... &
RE: Please Help - CIDR - How the bits work [7:75050]
Oh, and while I'm on the subject - why EIGRP? This is a proprietary Cisco Protocol. OK, I believe that Juniper may have implemented it, but to the best of my knowledge no one else has. Best regards, Dom Stocqueler SysDom Technologies Visit our website - www.sysdom.org -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Reimer, Fred Sent: 09 September 2003 22:03 To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] I guess my expectation and Cisco's, or at least their current expectations as listed on their web site, don't match then. By my definition a beginner should know about CIDR, EIGRP, and OSPF. It's not like they are inherently difficult to understand. People tend to make it sound like rocket science or voodoo magic. It's just a routing protocol folks. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: "Chuck Whose Road is Ever Shorter" [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 3:56 PM To: [EMAIL PROTECTED] Subject: Re: Please Help - CIDR - How the bits work [7:75050] ""Reimer, Fred"" wrote in message news:[EMAIL PROTECTED] > May be I had advanced access to the new NA material then ;-) In my > view, a > NA should be able to handle basic RIP, OSPF, EIGRP in a small to > medium sized network. That would certainly include CIDR. A NP, IMO, > would be for > advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a > mid-large sized network for connection to the Internet including > minimal BGP. IE, IMO, is for ISP engineers that have to deal with > extensive IS-IS, BGP using > all options, etc, and large to huge (global) networks. > > May be I'm just expecting too much, but if you don't understand CIDR > you shouldn't be allowed anywhere near a router, let alone be > responsible for configuring them. with all due respect, I disagree. CCNA is promoted by Cisco as being someone capable of designing and configuring a small network. http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certificati on_t ype_home.html "The CCNA certification (Cisco Certified Network Associate) indicates a foundation in and apprentice knowledge of networking. CCNA certified professionals can install, configure, and operate LAN, WAN, and dial access services for small networks (100 nodes or fewer), including but not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists." my experience has been that small nets have less if any need for CIDR knowledge or expertise. Cisco has over the past couple of years been slowly upping the ante, and I wish Cisco would get clear as to what skill sets are appropriate at what certification level. Cisco tends to be all over the map on this, and has been the netire time I have been playing at certification. But in general, I believe the idea is that CCxA is beginner, CCxP is intermediate, and CCIE is high level. as with all things certification related, YMMV. I've known CCNA's who manage large networks, and I've known CCIE's whose knowledge of certain specific areas was less than expert. As can be expected, depending on experience, job, place of employment, years in the field, etc. Chuck > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary information > which may be legally privileged. It is intended only for the named > recipient(s). If an addressing or transmission error has misdirected > the email, please notify the author by replying to this message. If > you are not the named recipient, you are not authorized to use, > disclose, distribute, copy, print > or rely on this email, and should immediately delete it from your computer. > > > -Original Message- > From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 12:33 PM > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > Reimer, Fred wrote: > > > > No offense, but this is CCNA material. > > Do they still tea
RE: Please Help - CIDR - How the bits work [7:75050]
Fred, check out the archives for Howard's piece on the difference between 'Rocket Science' and 'BGP' when at NASA. Best regards, Dom Stocqueler SysDom Technologies Visit our website - www.sysdom.org -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Reimer, Fred Sent: 09 September 2003 22:03 To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] I guess my expectation and Cisco's, or at least their current expectations as listed on their web site, don't match then. By my definition a beginner should know about CIDR, EIGRP, and OSPF. It's not like they are inherently difficult to understand. People tend to make it sound like rocket science or voodoo magic. It's just a routing protocol folks. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: "Chuck Whose Road is Ever Shorter" [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 3:56 PM To: [EMAIL PROTECTED] Subject: Re: Please Help - CIDR - How the bits work [7:75050] ""Reimer, Fred"" wrote in message news:[EMAIL PROTECTED] > May be I had advanced access to the new NA material then ;-) In my > view, a > NA should be able to handle basic RIP, OSPF, EIGRP in a small to > medium sized network. That would certainly include CIDR. A NP, IMO, > would be for > advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a > mid-large sized network for connection to the Internet including > minimal BGP. IE, IMO, is for ISP engineers that have to deal with > extensive IS-IS, BGP using > all options, etc, and large to huge (global) networks. > > May be I'm just expecting too much, but if you don't understand CIDR > you shouldn't be allowed anywhere near a router, let alone be > responsible for configuring them. with all due respect, I disagree. CCNA is promoted by Cisco as being someone capable of designing and configuring a small network. http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certificati on_t ype_home.html "The CCNA certification (Cisco Certified Network Associate) indicates a foundation in and apprentice knowledge of networking. CCNA certified professionals can install, configure, and operate LAN, WAN, and dial access services for small networks (100 nodes or fewer), including but not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists." my experience has been that small nets have less if any need for CIDR knowledge or expertise. Cisco has over the past couple of years been slowly upping the ante, and I wish Cisco would get clear as to what skill sets are appropriate at what certification level. Cisco tends to be all over the map on this, and has been the netire time I have been playing at certification. But in general, I believe the idea is that CCxA is beginner, CCxP is intermediate, and CCIE is high level. as with all things certification related, YMMV. I've known CCNA's who manage large networks, and I've known CCIE's whose knowledge of certain specific areas was less than expert. As can be expected, depending on experience, job, place of employment, years in the field, etc. Chuck > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary information > which may be legally privileged. It is intended only for the named > recipient(s). If an addressing or transmission error has misdirected > the email, please notify the author by replying to this message. If > you are not the named recipient, you are not authorized to use, > disclose, distribute, copy, print > or rely on this email, and should immediately delete it from your computer. > > > -Original Message- > From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 12:33 PM > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > Reimer, Fred wrote: > > > > No offense, but this is CCNA material. > > Do they still teach classful for CCNA, though? Perhaps the only thing
RE: Please Help - CIDR - How the bits work [7:75050]
And one last point, No LAN is an island, why two IG(P) protocols and no EG(P) protocol? A NA should at least a some understanding of how to connect to the outside world - when to use BGP and when not to. Sorry Fred, not having a go at you personally, but these are points we all need to think about. Best regards, Dom Stocqueler SysDom Technologies Visit our website - www.sysdom.org -Original Message- From: Dom [mailto:[EMAIL PROTECTED] Sent: 09 September 2003 23:37 To: 'Reimer, Fred'; '[EMAIL PROTECTED]' Subject: RE: Please Help - CIDR - How the bits work [7:75050] Oh, and while I'm on the subject - why EIGRP? This is a proprietary Cisco Protocol. OK, I believe that Juniper may have implemented it, but to the best of my knowledge no one else has. Best regards, Dom Stocqueler SysDom Technologies Visit our website - www.sysdom.org -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Reimer, Fred Sent: 09 September 2003 22:03 To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] I guess my expectation and Cisco's, or at least their current expectations as listed on their web site, don't match then. By my definition a beginner should know about CIDR, EIGRP, and OSPF. It's not like they are inherently difficult to understand. People tend to make it sound like rocket science or voodoo magic. It's just a routing protocol folks. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: "Chuck Whose Road is Ever Shorter" [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 3:56 PM To: [EMAIL PROTECTED] Subject: Re: Please Help - CIDR - How the bits work [7:75050] ""Reimer, Fred"" wrote in message news:[EMAIL PROTECTED] > May be I had advanced access to the new NA material then ;-) In my > view, a > NA should be able to handle basic RIP, OSPF, EIGRP in a small to > medium sized network. That would certainly include CIDR. A NP, IMO, > would be for > advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a > mid-large sized network for connection to the Internet including > minimal BGP. IE, IMO, is for ISP engineers that have to deal with > extensive IS-IS, BGP using > all options, etc, and large to huge (global) networks. > > May be I'm just expecting too much, but if you don't understand CIDR > you shouldn't be allowed anywhere near a router, let alone be > responsible for configuring them. with all due respect, I disagree. CCNA is promoted by Cisco as being someone capable of designing and configuring a small network. http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certificati on_t ype_home.html "The CCNA certification (Cisco Certified Network Associate) indicates a foundation in and apprentice knowledge of networking. CCNA certified professionals can install, configure, and operate LAN, WAN, and dial access services for small networks (100 nodes or fewer), including but not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists." my experience has been that small nets have less if any need for CIDR knowledge or expertise. Cisco has over the past couple of years been slowly upping the ante, and I wish Cisco would get clear as to what skill sets are appropriate at what certification level. Cisco tends to be all over the map on this, and has been the netire time I have been playing at certification. But in general, I believe the idea is that CCxA is beginner, CCxP is intermediate, and CCIE is high level. as with all things certification related, YMMV. I've known CCNA's who manage large networks, and I've known CCIE's whose knowledge of certain specific areas was less than expert. As can be expected, depending on experience, job, place of employment, years in the field, etc. Chuck > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary information > which may be legally privileged. It is intended only for the named > recipient(s). If an addressing or transmission error has misdirected > the email
RE: Please Help - CIDR - How the bits work [7:75050]
Dom wrote: > > And one last point, No LAN is an island, why two IG(P) > protocols and no > EG(P) protocol? > > A NA should at least a some understanding of how to connect to > the > outside world - when to use BGP and when not to. Default routing. Wouldn't we all be better off if CCNAs would stay away from BGP?? :-) Priscilla > > Sorry Fred, not having a go at you personally, but these are > points we > all need to think about. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > > -Original Message- > From: Dom [mailto:[EMAIL PROTECTED] > Sent: 09 September 2003 23:37 > To: 'Reimer, Fred'; '[EMAIL PROTECTED]' > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > Oh, and while I'm on the subject - why EIGRP? This is a > proprietary > Cisco Protocol. OK, I believe that Juniper may have implemented > it, but > to the best of my knowledge no one else has. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of > Reimer, Fred > Sent: 09 September 2003 22:03 > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > I guess my expectation and Cisco's, or at least their current > expectations as listed on their web site, don't match then. By > my > definition a beginner should know about CIDR, EIGRP, and OSPF. > It's not > like they are inherently difficult to understand. People tend > to make > it sound like rocket science or voodoo magic. It's just a > routing > protocol folks. > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA > 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary > information > which may be legally privileged. It is intended only for the > named > recipient(s). If an addressing or transmission error has > misdirected the > email, please notify the author by replying to this message. If > you are > not the named recipient, you are not authorized to use, > disclose, > distribute, copy, print or rely on this email, and should > immediately > delete it from your computer. > > > -Original Message- > From: "Chuck Whose Road is Ever Shorter" > [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 3:56 PM > To: [EMAIL PROTECTED] > Subject: Re: Please Help - CIDR - How the bits work [7:75050] > > ""Reimer, Fred"" wrote in message > news:[EMAIL PROTECTED] > > May be I had advanced access to the new NA material then ;-) > In my > > view, > a > > NA should be able to handle basic RIP, OSPF, EIGRP in a small > to > > medium sized network. That would certainly include CIDR. A > NP, IMO, > > would be > for > > advanced RIP, OSPF, EIGRP, and basic BGP, like for > configuring a > > mid-large sized network for connection to the Internet > including > > minimal BGP. IE, IMO, is for ISP engineers that have to deal > with > > extensive IS-IS, BGP > using > > all options, etc, and large to huge (global) networks. > > > > May be I'm just expecting too much, but if you don't > understand CIDR > > you shouldn't be allowed anywhere near a router, let alone be > > responsible for configuring them. > > > with all due respect, I disagree. CCNA is promoted by Cisco as > being > someone capable of designing and configuring a small network. > > http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certificati > on_t > ype_home.html > > "The CCNA certification (Cisco Certified Network Associate) > indicates a > foundation in and apprentice knowledge of networking. CCNA > certified > professionals can install, configure, and operate LAN, WAN, and > dial > access services for small networks (100 nodes or fewer), > including but > not limited to use of these protocols: IP, IGRP, Serial, Frame > Relay, IP > RIP, VLANs, RIP, Ethernet, Access Lists." > > my experience has been that small nets have less if any need > for CIDR > knowledge or expertise. > > Cisco has over the past couple of years been slowly upping the > ante, and > I wish Cisco would get clear as to what skill sets are > appropriate at > what certification level. Cisco tends to be all over the map on > this, > and has been the netire time I have been playing
RE: Please Help - CIDR - How the bits work [7:75050]
Priscilla, As much as I respect your great knowledge I must disagree. If CCNAs had some small amount of understanding of BGP (and I mean small) they would stop asking about registered AS numbers etc when trying to set up so-called resilient connections, usually to/from the same providers. Can we not tell them that it is grown up stuff and they will learn ***more*** about it later - Just give them an overview. Just my 0.02 GPBs Dom -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: 10 September 2003 00:32 To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] Dom wrote: > > And one last point, No LAN is an island, why two IG(P) protocols and > no > EG(P) protocol? > > A NA should at least a some understanding of how to connect to the > outside world - when to use BGP and when not to. Default routing. Wouldn't we all be better off if CCNAs would stay away from BGP?? :-) Priscilla > > Sorry Fred, not having a go at you personally, but these are points we > all need to think about. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > > -Original Message- > From: Dom [mailto:[EMAIL PROTECTED] > Sent: 09 September 2003 23:37 > To: 'Reimer, Fred'; '[EMAIL PROTECTED]' > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > Oh, and while I'm on the subject - why EIGRP? This is a proprietary > Cisco Protocol. OK, I believe that Juniper may have implemented > it, but > to the best of my knowledge no one else has. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf > Of Reimer, Fred > Sent: 09 September 2003 22:03 > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > I guess my expectation and Cisco's, or at least their current > expectations as listed on their web site, don't match then. By my > definition a beginner should know about CIDR, EIGRP, and OSPF. > It's not > like they are inherently difficult to understand. People tend > to make > it sound like rocket science or voodoo magic. It's just a > routing > protocol folks. > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary information > which may be legally privileged. It is intended only for the > named > recipient(s). If an addressing or transmission error has > misdirected the > email, please notify the author by replying to this message. If > you are > not the named recipient, you are not authorized to use, > disclose, > distribute, copy, print or rely on this email, and should > immediately > delete it from your computer. > > > -Original Message- > From: "Chuck Whose Road is Ever Shorter" > [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 3:56 PM > To: [EMAIL PROTECTED] > Subject: Re: Please Help - CIDR - How the bits work [7:75050] > > ""Reimer, Fred"" wrote in message > news:[EMAIL PROTECTED] > > May be I had advanced access to the new NA material then ;-) > In my > > view, > a > > NA should be able to handle basic RIP, OSPF, EIGRP in a small > to > > medium sized network. That would certainly include CIDR. A > NP, IMO, > > would be > for > > advanced RIP, OSPF, EIGRP, and basic BGP, like for > configuring a > > mid-large sized network for connection to the Internet > including > > minimal BGP. IE, IMO, is for ISP engineers that have to deal > with > > extensive IS-IS, BGP > using > > all options, etc, and large to huge (global) networks. > > > > May be I'm just expecting too much, but if you don't > understand CIDR > > you shouldn't be allowed anywhere near a router, let alone be > > responsible for configuring them. > > > with all due respect, I disagree. CCNA is promoted by Cisco as being > someone capable of designing and configuring a small network. > > http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certifica > ti > on_t > ype_home.html > > "The CCNA certification (Cisco Certified Network Associate) indicates > a foundation in and apprentice knowledge of networking. CCNA > certified > professionals can install, configure, and operate LAN, WAN, and > dial > access services for small networks (10
RE: Please Help - CIDR - How the bits work [7:75050]
Tom, In the old CCNA books if a question came up about how many subnets could be formed from a block - the all zeros and all ones subnets were not counted. Does this still hold with the new curriculum? > -Original Message- > From: Tom Lisa [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 3:54 PM > To: [EMAIL PROTECTED] > Subject: Re: Please Help - CIDR - How the bits work [7:75050] > > > We are now teaching VLSM/CIDR in the CCNA curriculum. > > Prof. Tom Lisa, CCAI > Community College of Southern Nevada > Cisco ATC/Regional Networking Academy > "Cunctando restituit rem" Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75142&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Re: Please Help - CIDR - How the bits work [7:75050]
No, the new curriculum recognizes the subnet zero command. Prof. Tom Lisa, CCAI Community College of Southern Nevada Cisco ATC/Regional Networking Academy "Cunctando restituit rem" Daniel Cotts wrote: > Tom, > In the old CCNA books if a question came up about how many subnets could be > formed from a block - the all zeros and all ones subnets were not counted. > Does this still hold with the new curriculum? > > > -Original Message- > > From: Tom Lisa [mailto:[EMAIL PROTECTED] > > Sent: Tuesday, September 09, 2003 3:54 PM > > To: [EMAIL PROTECTED] > > Subject: Re: Please Help - CIDR - How the bits work [7:75050] > > > > > > We are now teaching VLSM/CIDR in the CCNA curriculum. > > > > Prof. Tom Lisa, CCAI > > Community College of Southern Nevada > > Cisco ATC/Regional Networking Academy > > "Cunctando restituit rem" > **Please support GroupStudy by purchasing from the GroupStudy Store: > http://shop.groupstudy.com > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75149&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
At 10:36 PM + 9/9/03, Dom wrote: >Fred, check out the archives for Howard's piece on the difference >between 'Rocket Science' and 'BGP' when at NASA. > >Best regards, > >Dom Stocqueler >SysDom Technologies >Visit our website - www.sysdom.org Seriously, I've fought a battle for many years with Cisco Training. I believe the fundamental problem they _create_ is insisting on teaching classful and dotted decimal notation first. When I've given private classes -- ICRC, the older RSC, etc. -- I always began discussing addressing in binary, got people used to the idea of prefix length, then introduced dotted decimal as a means of representation, and then introduced classful addressing as a historic concept. Students were always able to go right into classless routing without any trouble. There are some nice examples in RFC 1878. RFCs 1517-1520 give the main background, although there are some earlier papers on "supernetting". With all mercenary disclaimers, I also recommend my book, _Designing Addressing Architectures for Routing and Switching_, and my recent IPv4/IPv6 tutorial on Certification Zone. >-Original Message- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of >Reimer, Fred >Sent: 09 September 2003 22:03 >To: [EMAIL PROTECTED] >Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > >I guess my expectation and Cisco's, or at least their current >expectations as listed on their web site, don't match then. By my >definition a beginner should know about CIDR, EIGRP, and OSPF. It's not >like they are inherently difficult to understand. People tend to make >it sound like rocket science or voodoo magic. It's just a routing >protocol folks. > >Fred Reimer - CCNA > >-Original Message- >From: "Chuck Whose Road is Ever Shorter" [mailto:[EMAIL PROTECTED] >Sent: Tuesday, September 09, 2003 3:56 PM >To: [EMAIL PROTECTED] >Subject: Re: Please Help - CIDR - How the bits work [7:75050] > >""Reimer, Fred"" wrote in message >news:[EMAIL PROTECTED] >> May be I had advanced access to the new NA material then ;-) In my >> view, >a >> NA should be able to handle basic RIP, OSPF, EIGRP in a small to >> medium sized network. That would certainly include CIDR. A NP, IMO, >> would be >for >> advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a >> mid-large sized network for connection to the Internet including >> minimal BGP. IE, IMO, is for ISP engineers that have to deal with >> extensive IS-IS, BGP >using >> all options, etc, and large to huge (global) networks. Historically, the R&S CCIE has been aimed at large, or medium to large, enterprises. It doesn't begin to explore real-world BGP. > > >> May be I'm just expecting too much, but if you don't understand CIDR >> you shouldn't be allowed anywhere near a router, let alone be >> responsible for configuring them. > > >with all due respect, I disagree. CCNA is promoted by Cisco as being >someone capable of designing and configuring a small network. > >http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certificati >on_t >ype_home.html > >"The CCNA certification (Cisco Certified Network Associate) indicates a >foundation in and apprentice knowledge of networking. CCNA certified >professionals can install, configure, and operate LAN, WAN, and dial >access services for small networks (100 nodes or fewer), including but >not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP >RIP, VLANs, RIP, Ethernet, Access Lists." > >my experience has been that small nets have less if any need for CIDR >knowledge or expertise. > >Cisco has over the past couple of years been slowly upping the ante, and >I wish Cisco would get clear as to what skill sets are appropriate at >what certification level. Cisco tends to be all over the map on this, >and has been the netire time I have been playing at certification. But >in general, I believe the idea is that CCxA is beginner, CCxP is >intermediate, and CCIE is high level. > >as with all things certification related, YMMV. I've known CCNA's who >manage large networks, and I've known CCIE's whose knowledge of certain >specific areas was less than expert. As can be expected, depending on >experience, job, place of employment, years in the field, etc. > >Chuck > > >> >> Fred Reimer - CCNA >> >> >> Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 >> Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 >> >> >>
RE: Please Help - CIDR - How the bits work [7:75050]
At 11:32 PM + 9/9/03, Priscilla Oppenheimer wrote: >Dom wrote: >> >> And one last point, No LAN is an island, why two IG(P) >> protocols and no >> EG(P) protocol? >> >> A NA should at least a some understanding of how to connect to >> the >> outside world - when to use BGP and when not to. > >Default routing. Wouldn't we all be better off if CCNAs would stay away from >BGP?? :-) > >Priscilla When fingerpointing in quite a number of external connectivity problems, I have often found de fault is due to the lack of default. Cisco hardly helps this by discriminating against static and default routes in the CCIE lab. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75153&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
>Oh, and while I'm on the subject - why EIGRP? This is a proprietary >Cisco Protocol. OK, I believe that Juniper may have implemented it, but >to the best of my knowledge no one else has. Can we say account control? EIGRP is somewhat less resource intensive than link state protocols under some circumstances, and may be more tolerant of certain errors. Since AppleTalk and IPX have been deemphasized, it's harder and harder to justify. Yes, it's topologically more flexible than OSPF and ISIS, but that, IMHO, is not necessarily a good thing for someone who doesn't really understand when not to use hierarchical topology. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75152&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
No offense, but this is CCNA material. If you are going for your CCNP, then you should already have your CCNA and know the answer. But anyway... If you need a network with 400 hosts, the smallest subnet would have a /23 mask. So take the first part of your given network and assign it to that: 192.168.24.0/23 (192.168.24.0-192.168.25.255) Then you need one with 200 hosts. Well, that could fit within a /24 subnet, so assign the next available to that: 192.168.26.0/24 (192.168.26.0-192.168.26.255) Now you only have 192.168.27.0/24 left from the original 192.168.24.0/23 (which covered 192.168.24.0-192.168.27.255). You need two 50's, so that should fit within /26 subnets each. Assign them: 192.168.27.0/26 (192.168.27.0-192.168.27.63) 192.168.27.64/26 (192.168.27.64-192.168.27.191) Finally, you need three subnets that can have two hosts each, which would fit within /30 subnets. So assign: 192.168.27.192/30 192.168.27.196/30 192.168.27.200/30 Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Steven Aiello [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 8:02 AM To: [EMAIL PROTECTED] Subject: Please Help - CIDR - How the bits work [7:75050] I just started my routing class for my CCNP. We are covering CIDR. The book is VEERY vague on how the bit patterns break down and are used. This was a problem posed in one of my CCNP labs I have network number 192.168.24.0 / 22 from this I need networks with 400 hosts 200 hosts 50 hosts 50 hosts 2 hosts (for serial int - no ip un-numbered allowed ) 2 hosts 2 hosts Also no NATing Thanks all I really could use the help Steve **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html This email has been scanned for all viruses by the MessageLabs Email Security System. For more information on a proactive email security service working around the clock, around the globe, visit http://www.messagelabs.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75164&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
BLIMEY !!! this is getting a little heated L+G`s . i personally believe that when i got my CCNA if i had been asked to configure BGP (even Basic) on an internet connecting router for a small-medium sized company...i would have run away screaming... Ask yourselfs this there are three grade`s of Certifications at cisco Associate Profesisional Expert from a company manager`s point-of-view (no offence fred) Whom would you prefer be touching your internet facing router ... yes i am aware that to most of us they don`t mean tuppence (i.e howard/pris) but the plan truth is people NOT in the know rely on the badges >From: "Howard C. Berkowitz" >Reply-To: "Howard C. Berkowitz" >To: [EMAIL PROTECTED] >Subject: RE: Please Help - CIDR - How the bits work [7:75050] >Date: Wed, 10 Sep 2003 03:36:57 GMT > >At 11:32 PM + 9/9/03, Priscilla Oppenheimer wrote: > >Dom wrote: > >> > >> And one last point, No LAN is an island, why two IG(P) > >> protocols and no > >> EG(P) protocol? > >> > >> A NA should at least a some understanding of how to connect to > >> the > >> outside world - when to use BGP and when not to. > > > >Default routing. Wouldn't we all be better off if CCNAs would stay away >from > >BGP?? :-) > > > >Priscilla > >When fingerpointing in quite a number of external connectivity >problems, I have often found de fault is due to the lack of default. >Cisco hardly helps this by discriminating against static and default >routes in the CCIE lab. >**Please support GroupStudy by purchasing from the GroupStudy Store: >http://shop.groupstudy.com >FAQ, list archives, and subscription info: >http://www.groupstudy.com/list/cisco.html _ Tired of 56k? Get a FREE BT Broadband connection http://www.msn.co.uk/specials/btbroadband Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75166&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Re: Please Help - CIDR - How the bits work [7:75050]
Fred, OSPF was just moved into the CCNA 3.0 Acad. which is JUST being released now. I wish we would have coverd that, and other things you mention. Steve Reimer, Fred wrote: > May be I had advanced access to the new NA material then ;-) In my view, a > NA should be able to handle basic RIP, OSPF, EIGRP in a small to medium > sized network. That would certainly include CIDR. A NP, IMO, would be for > advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a mid-large > sized network for connection to the Internet including minimal BGP. IE, > IMO, is for ISP engineers that have to deal with extensive IS-IS, BGP using > all options, etc, and large to huge (global) networks. > > May be I'm just expecting too much, but if you don't understand CIDR you > shouldn't be allowed anywhere near a router, let alone be responsible for > configuring them. > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary information which > may be legally privileged. It is intended only for the named recipient(s). > If an addressing or transmission error has misdirected the email, please > notify the author by replying to this message. If you are not the named > recipient, you are not authorized to use, disclose, distribute, copy, print > or rely on this email, and should immediately delete it from your computer. > > > -Original Message- > From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 12:33 PM > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > Reimer, Fred wrote: > >>No offense, but this is CCNA material. > > > Do they still teach classful for CCNA, though? Perhaps the only thing that's > hard for him is that 192.168.24.0 has a mask of 255.255.255.0 in a classful > system. Moving the prefix over to the left of that classful boundary isn't > something they teach for CCNA yet. (They will soon. The new Networking > Academy books teach it from the start now.) > > Priscilla > > >>If you are going for >>your CCNP, then >>you should already have your CCNA and know the answer. But >>anyway... >> >>If you need a network with 400 hosts, the smallest subnet would >>have a /23 >>mask. So take the first part of your given network and assign >>it to that: >> >>192.168.24.0/23 (192.168.24.0-192.168.25.255) >> >>Then you need one with 200 hosts. Well, that could fit within >>a /24 subnet, >>so assign the next available to that: >> >>192.168.26.0/24 (192.168.26.0-192.168.26.255) >> >>Now you only have 192.168.27.0/24 left from the original >>192.168.24.0/23 >>(which covered 192.168.24.0-192.168.27.255). You need two >>50's, so that >>should fit within /26 subnets each. Assign them: >> >>192.168.27.0/26 (192.168.27.0-192.168.27.63) >>192.168.27.64/26 (192.168.27.64-192.168.27.191) >> >>Finally, you need three subnets that can have two hosts each, >>which would >>fit within /30 subnets. So assign: >> >>192.168.27.192/30 >>192.168.27.196/30 >>192.168.27.200/30 >> >> >>Fred Reimer - CCNA >> >> >>Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA >>30338 >>Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 >> >> >>NOTICE; This email contains confidential or proprietary >>information which >>may be legally privileged. It is intended only for the named >>recipient(s). >>If an addressing or transmission error has misdirected the >>email, please >>notify the author by replying to this message. If you are not >>the named >>recipient, you are not authorized to use, disclose, distribute, >>copy, print >>or rely on this email, and should immediately delete it from >>your computer. >> >> >>-Original Message- >>From: Steven Aiello [mailto:[EMAIL PROTECTED] >>Sent: Tuesday, September 09, 2003 8:02 AM >>To: [EMAIL PROTECTED] >>Subject: Please Help - CIDR - How the bits work [7:75050] >> >>I just started my routing class for my CCNP. We are covering >>CIDR. The >>book is VEERY vague on how the bit patterns break down and >>are used. >> >> >>This was a problem posed in one of my CCNP labs >> >>I have network number >> >>192.168.24.0 / 22 >> >>from this I need >>networks with >> >>400 hosts
RE: Please Help - CIDR - How the bits work [7:75050]
Hi there, There is a great link for al this you should check out: http://www.3com.com/other/pdfs/infra/corpinfo/en_US/501302.pdf Cheers, Kenan Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75174&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Here's a great resource: pad http://www.nanog.org/isp.html#cidr scroll down to CIDR and download "Understanding IP Addressing: Everything You Ever Wanted to Know" by Chuck Semeria Looking at your specific problem - think in powers of two. 400 nodes is greater than 256 but less than 512. Use /23 out of your allocation. 200 is less than 256 so use a /24. 50 is greater than 32 and less than 64 so use a /26 for each. The serial links each need a /30. Probably best to take the last /28 from the allocation and break it down into four /30s. > -Original Message- > From: Steven Aiello [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 7:02 AM > To: [EMAIL PROTECTED] > Subject: Please Help - CIDR - How the bits work [7:75050] > > > I just started my routing class for my CCNP. We are covering > CIDR. The > book is VEERY vague on how the bit patterns break down > and are used. > > > This was a problem posed in one of my CCNP labs > > I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts > > Also no NATing > > Thanks all I really could use the help > > Steve **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html This email has been scanned for all viruses by the MessageLabs Email Security System. For more information on a proactive email security service working around the clock, around the globe, visit http://www.messagelabs.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75171&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Re: Please Help - CIDR - How the bits work [7:75050]
I get the same results as Marko, but this may lay it out so you (and others) can see the development: IP address = 32 bits Network portion = 22 bits Host portion = 10 bits Total addresses for host portion = 2^10 = 1024 Start with 192.168.24.0/22 Focus on the 3rd octet (network_host): 000110_00 400 hosts requires 9 bits (2^8 = 256, 2^9 = 512) and you will have some left in this block divide the /22 into two blocks of 512 addresses each: 0001100_0 (.24/23) and 000_0 (.26/23) use .24/23 for the 400-host network 200 hosts requires 8 bits (2^7 = 128, 2^8 = 256) and there will be some left in this block, too divide the .26/25 into 2 blocks of 256 addresses each: 0000 (.26/24) and 0001 (.27/24) use .26/24 for the 200-host network 50 hosts requires 6 bits (2^5 = 32, 2^6 = 64) and you will again have some leftovers divide the .27/24 into 4 blocks of 64 addresses each now looking at the 4th octet: 00_00 (.0/26), 01_00 (.64/26), 10_00 (.128/26), and 11_00 (.192/26) use the first two for the 50-host networks and the rest is easy My personal rule is to always start with the biggest blocks and work down from there. HTH Annlee Steven Aiello wrote: > I just started my routing class for my CCNP. We are covering CIDR. The > book is VEERY vague on how the bit patterns break down and are used. > > > This was a problem posed in one of my CCNP labs > > I have network number > > 192.168.24.0 / 22 > > from this I need > networks with > > 400 hosts > 200 hosts > 50 hosts > 50 hosts > 2 hosts (for serial int - no ip un-numbered allowed ) > 2 hosts > 2 hosts > > Also no NATing > > Thanks all I really could use the help > > Steve > **Please support GroupStudy by purchasing from the GroupStudy Store: > http://shop.groupstudy.com > FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html This email has been scanned for all viruses by the MessageLabs Email Security System. For more information on a proactive email security service working around the clock, around the globe, visit http://www.messagelabs.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75172&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
No reason to be sorry! I'm all for "vigorous" discussion ;-)
No BGP in the NA because we are talking about SMALL to medium business.
Yes, they should know about how to connect up to the Internet, using a
default route, etc. But you are not going to find that many ISPs, if any,
that are willing to setup a BGP peer with a store-front business with a 16
address space public network (or even granted they are given a /24 public
subnet). If you find any, let me know!
That's why I say EGP for NP. A medium to large business certainly may need
EGP expertise.
And I suppose that's a slight difference in the way people think about the
different certification levels. When I say RIP, IGRP, EIGRP, OSPF should be
requirements for a NA I mean the candidates should be }experts{ in those
protocols. Not just having a passing understanding, have read about it in a
book once, or used some study guide to rote-memorize answers to common
questions.
So, on the one hand I think the standards should be tougher, requiring
"expert" level knowledge for the IGP's, and on the other I don't think a NA
needs to know anything about EGP's.
Fred Reimer - CCNA
Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338
Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050
NOTICE; This email contains confidential or proprietary information which
may be legally privileged. It is intended only for the named recipient(s).
If an addressing or transmission error has misdirected the email, please
notify the author by replying to this message. If you are not the named
recipient, you are not authorized to use, disclose, distribute, copy, print
or rely on this email, and should immediately delete it from your computer.
-Original Message-
From: Dom [mailto:[EMAIL PROTECTED]
Sent: Tuesday, September 09, 2003 6:59 PM
To: [EMAIL PROTECTED]; 'Reimer, Fred'; [EMAIL PROTECTED]
Subject: RE: Please Help - CIDR - How the bits work [7:75050]
And one last point, No LAN is an island, why two IG(P) protocols and no
EG(P) protocol?
A NA should at least a some understanding of how to connect to the
outside world - when to use BGP and when not to.
Sorry Fred, not having a go at you personally, but these are points we
all need to think about.
Best regards,
Dom Stocqueler
SysDom Technologies
Visit our website - www.sysdom.org
-Original Message-
From: Dom [mailto:[EMAIL PROTECTED]
Sent: 09 September 2003 23:37
To: 'Reimer, Fred'; '[EMAIL PROTECTED]'
Subject: RE: Please Help - CIDR - How the bits work [7:75050]
Oh, and while I'm on the subject - why EIGRP? This is a proprietary
Cisco Protocol. OK, I believe that Juniper may have implemented it, but
to the best of my knowledge no one else has.
Best regards,
Dom Stocqueler
SysDom Technologies
Visit our website - www.sysdom.org
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of
Reimer, Fred
Sent: 09 September 2003 22:03
To: [EMAIL PROTECTED]
Subject: RE: Please Help - CIDR - How the bits work [7:75050]
I guess my expectation and Cisco's, or at least their current
expectations as listed on their web site, don't match then. By my
definition a beginner should know about CIDR, EIGRP, and OSPF. It's not
like they are inherently difficult to understand. People tend to make
it sound like rocket science or voodoo magic. It's just a routing
protocol folks.
Fred Reimer - CCNA
Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338
Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050
NOTICE; This email contains confidential or proprietary information
which may be legally privileged. It is intended only for the named
recipient(s). If an addressing or transmission error has misdirected the
email, please notify the author by replying to this message. If you are
not the named recipient, you are not authorized to use, disclose,
distribute, copy, print or rely on this email, and should immediately
delete it from your computer.
-Original Message-
From: "Chuck Whose Road is Ever Shorter" [mailto:[EMAIL PROTECTED]
Sent: Tuesday, September 09, 2003 3:56 PM
To: [EMAIL PROTECTED]
Subject: Re: Please Help - CIDR - How the bits work [7:75050]
""Reimer, Fred"" wrote in message
news:[EMAIL PROTECTED]
> May be I had advanced access to the new NA material then ;-) In my
> view,
a
> NA should be able to handle basic RIP, OSPF, EIGRP in a small to
> medium sized network. That would certainly include CIDR. A NP, IMO,
> would be
for
> advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a
> mid-large sized network for connection to the Internet including
> minimal BGP. IE, IMO, is for ISP engineers that have to deal with
> extensive IS-IS, BGP
using
> all options, etc, and large to huge (global) networks.
>
> May be I'm just exp
RE: Please Help - CIDR - How the bits work [7:75050]
Yes! Even I would not feel comfortable configuring BGP in a production environment yet, and although I don't have my CCNP yet, I did pass the routing and switching tests. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 7:32 PM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] Dom wrote: > > And one last point, No LAN is an island, why two IG(P) > protocols and no > EG(P) protocol? > > A NA should at least a some understanding of how to connect to > the > outside world - when to use BGP and when not to. Default routing. Wouldn't we all be better off if CCNAs would stay away from BGP?? :-) Priscilla > > Sorry Fred, not having a go at you personally, but these are > points we > all need to think about. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > > -Original Message- > From: Dom [mailto:[EMAIL PROTECTED] > Sent: 09 September 2003 23:37 > To: 'Reimer, Fred'; '[EMAIL PROTECTED]' > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > Oh, and while I'm on the subject - why EIGRP? This is a > proprietary > Cisco Protocol. OK, I believe that Juniper may have implemented > it, but > to the best of my knowledge no one else has. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of > Reimer, Fred > Sent: 09 September 2003 22:03 > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > I guess my expectation and Cisco's, or at least their current > expectations as listed on their web site, don't match then. By > my > definition a beginner should know about CIDR, EIGRP, and OSPF. > It's not > like they are inherently difficult to understand. People tend > to make > it sound like rocket science or voodoo magic. It's just a > routing > protocol folks. > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA > 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary > information > which may be legally privileged. It is intended only for the > named > recipient(s). If an addressing or transmission error has > misdirected the > email, please notify the author by replying to this message. If > you are > not the named recipient, you are not authorized to use, > disclose, > distribute, copy, print or rely on this email, and should > immediately > delete it from your computer. > > > -Original Message- > From: "Chuck Whose Road is Ever Shorter" > [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 3:56 PM > To: [EMAIL PROTECTED] > Subject: Re: Please Help - CIDR - How the bits work [7:75050] > > ""Reimer, Fred"" wrote in message > news:[EMAIL PROTECTED] > > May be I had advanced access to the new NA material then ;-) > In my > > view, > a > > NA should be able to handle basic RIP, OSPF, EIGRP in a small > to > > medium sized network. That would certainly include CIDR. A > NP, IMO, > > would be > for > > advanced RIP, OSPF, EIGRP, and basic BGP, like for > configuring a > > mid-large sized network for connection to the Internet > including > > minimal BGP. IE, IMO, is for ISP engineers that have to deal > with > > extensive IS-IS, BGP > using > > all options, etc, and large to huge (global) networks. > > > > May be I'm just expecting too much, but if you don't > understand CIDR > > you shouldn't be allowed anywhere near a router, let alone be > > responsible for configuring them. > > > with all due respect, I disagree. CCNA is promoted by Cisco as > being > someone capable of designing and configuring a small network. > > http:/
RE: Please Help - CIDR - How the bits work [7:75050]
True. The primary reasons would be that Cisco is the market leader, especially in SMB, and 2nd would be that while proprietary, the workings of the protocol certainly are not. It is well-documented. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Dom [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 6:37 PM To: 'Reimer, Fred'; [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] Oh, and while I'm on the subject - why EIGRP? This is a proprietary Cisco Protocol. OK, I believe that Juniper may have implemented it, but to the best of my knowledge no one else has. Best regards, Dom Stocqueler SysDom Technologies Visit our website - www.sysdom.org -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Reimer, Fred Sent: 09 September 2003 22:03 To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] I guess my expectation and Cisco's, or at least their current expectations as listed on their web site, don't match then. By my definition a beginner should know about CIDR, EIGRP, and OSPF. It's not like they are inherently difficult to understand. People tend to make it sound like rocket science or voodoo magic. It's just a routing protocol folks. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: "Chuck Whose Road is Ever Shorter" [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 3:56 PM To: [EMAIL PROTECTED] Subject: Re: Please Help - CIDR - How the bits work [7:75050] ""Reimer, Fred"" wrote in message news:[EMAIL PROTECTED] > May be I had advanced access to the new NA material then ;-) In my > view, a > NA should be able to handle basic RIP, OSPF, EIGRP in a small to > medium sized network. That would certainly include CIDR. A NP, IMO, > would be for > advanced RIP, OSPF, EIGRP, and basic BGP, like for configuring a > mid-large sized network for connection to the Internet including > minimal BGP. IE, IMO, is for ISP engineers that have to deal with > extensive IS-IS, BGP using > all options, etc, and large to huge (global) networks. > > May be I'm just expecting too much, but if you don't understand CIDR > you shouldn't be allowed anywhere near a router, let alone be > responsible for configuring them. with all due respect, I disagree. CCNA is promoted by Cisco as being someone capable of designing and configuring a small network. http://www.cisco.com/en/US/learning/le3/le2/le0/le9/learning_certificati on_t ype_home.html "The CCNA certification (Cisco Certified Network Associate) indicates a foundation in and apprentice knowledge of networking. CCNA certified professionals can install, configure, and operate LAN, WAN, and dial access services for small networks (100 nodes or fewer), including but not limited to use of these protocols: IP, IGRP, Serial, Frame Relay, IP RIP, VLANs, RIP, Ethernet, Access Lists." my experience has been that small nets have less if any need for CIDR knowledge or expertise. Cisco has over the past couple of years been slowly upping the ante, and I wish Cisco would get clear as to what skill sets are appropriate at what certification level. Cisco tends to be all over the map on this, and has been the netire time I have been playing at certification. But in general, I believe the idea is that CCxA is beginner, CCxP is intermediate, and CCIE is high level. as with all things certification related, YMMV. I've known CCNA's who manage large networks, and I've known CCIE's whose knowledge of certain specific areas was less than expert. As can be expected, depending on experience, job, place of employment, years in the field, etc. Chuck >
RE: Please Help - CIDR - How the bits work [7:75050]
Yes, but the CCIE labs are supposed to be for ISP level engineers, who almost certainly won't be using default routes most of the time. It should be assumed that by the time you get to the CCIE level you have much experience in default routing. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Howard C. Berkowitz [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 11:37 PM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] At 11:32 PM + 9/9/03, Priscilla Oppenheimer wrote: >Dom wrote: >> >> And one last point, No LAN is an island, why two IG(P) >> protocols and no >> EG(P) protocol? >> >> A NA should at least a some understanding of how to connect to >> the >> outside world - when to use BGP and when not to. > >Default routing. Wouldn't we all be better off if CCNAs would stay away from >BGP?? :-) > >Priscilla When fingerpointing in quite a number of external connectivity problems, I have often found de fault is due to the lack of default. Cisco hardly helps this by discriminating against static and default routes in the CCIE lab. **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75184&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
I've always liked hex myself. A hex mask of FF.FF.F8.00 can be written as F800 and still mean the same thing. You obviously can't do that with 255.255.128.0 (255.255.128.0 != 2,552,551,280). While binary works the same way as hex in this manner, it is much to long for my tastes. Plus, hex is used a lot in programming languages when using values in bitmasks, so I'm more familiar with it. Also, there are only 5 hex numbers that you need to memorize for masks, F 0 8 C and E. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Howard C. Berkowitz [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 11:32 PM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] At 10:36 PM + 9/9/03, Dom wrote: >Fred, check out the archives for Howard's piece on the difference >between 'Rocket Science' and 'BGP' when at NASA. > >Best regards, > >Dom Stocqueler >SysDom Technologies >Visit our website - www.sysdom.org Seriously, I've fought a battle for many years with Cisco Training. I believe the fundamental problem they _create_ is insisting on teaching classful and dotted decimal notation first. When I've given private classes -- ICRC, the older RSC, etc. -- I always began discussing addressing in binary, got people used to the idea of prefix length, then introduced dotted decimal as a means of representation, and then introduced classful addressing as a historic concept. Students were always able to go right into classless routing without any trouble. There are some nice examples in RFC 1878. RFCs 1517-1520 give the main background, although there are some earlier papers on "supernetting". With all mercenary disclaimers, I also recommend my book, _Designing Addressing Architectures for Routing and Switching_, and my recent IPv4/IPv6 tutorial on Certification Zone. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75185&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Oh, it's just getting fun. It's not like we are flaming anyone. We are just expressing our opinions! ;-) I'd agree with you. No BGP for NA's. And as far as who I'd want touching my Internet facing router, it would depend on what type of business it was. If it was a small business, where all they need is a default router that is propagated, I sure as heck would think that an NA would be able to handle that. If it was a large business with say a semi-extensive private WAN with multiple entries into the Internet, I'd definitely prefer at least a NP. If it was a company with dual ISP routing that incorporated BGP, then a NP might be able to handle it, but I would definitely prefer an IE. For ISP's, anyone that would even think of touching the backbone routers I would hope would be IE level, if not certified. It's the experience that counts to me, not necessarily the cert level. Heck, I only have my CCNA so far, but I'd hazard to guess that I have more practical experience than a certain double CCIE that I know. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Stephen Skinner [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 10, 2003 6:33 AM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] BLIMEY !!! this is getting a little heated L+G`s . i personally believe that when i got my CCNA if i had been asked to configure BGP (even Basic) on an internet connecting router for a small-medium sized company...i would have run away screaming... Ask yourselfs this there are three grade`s of Certifications at cisco Associate Profesisional Expert from a company manager`s point-of-view (no offence fred) Whom would you prefer be touching your internet facing router ... yes i am aware that to most of us they don`t mean tuppence (i.e howard/pris) but the plan truth is people NOT in the know rely on the badges >From: "Howard C. Berkowitz" >Reply-To: "Howard C. Berkowitz" >To: [EMAIL PROTECTED] >Subject: RE: Please Help - CIDR - How the bits work [7:75050] >Date: Wed, 10 Sep 2003 03:36:57 GMT > >At 11:32 PM + 9/9/03, Priscilla Oppenheimer wrote: > >Dom wrote: > >> > >> And one last point, No LAN is an island, why two IG(P) > >> protocols and no > >> EG(P) protocol? > >> > >> A NA should at least a some understanding of how to connect to > >> the > >> outside world - when to use BGP and when not to. > > > >Default routing. Wouldn't we all be better off if CCNAs would stay away >from > >BGP?? :-) > > > >Priscilla > >When fingerpointing in quite a number of external connectivity >problems, I have often found de fault is due to the lack of default. >Cisco hardly helps this by discriminating against static and default >routes in the CCIE lab. >**Please support GroupStudy by purchasing from the GroupStudy Store: >http://shop.groupstudy.com >FAQ, list archives, and subscription info: >http://www.groupstudy.com/list/cisco.html _ Tired of 56k? Get a FREE BT Broadband connection http://www.msn.co.uk/specials/btbroadband **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75188&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
At 11:40 AM -0400 9/10/03, Reimer, Fred wrote: >I've always liked hex myself. A hex mask of FF.FF.F8.00 can be written as >F800 and still mean the same thing. You obviously can't do that with >255.255.128.0 (255.255.128.0 != 2,552,551,280). While binary works the same >way as hex in this manner, it is much to long for my tastes. Plus, hex is >used a lot in programming languages when using values in bitmasks, so I'm >more familiar with it. Also, there are only 5 hex numbers that you need to >memorize for masks, F 0 8 C and E. > >Fred Reimer - CCNA I can live very easily with hex or binary. The problem is dotted decimal. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75194&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
At 11:34 AM -0400 9/10/03, Reimer, Fred wrote: >Yes, but the CCIE labs are supposed to be for ISP level engineers, who >almost certainly won't be using default routes most of the time. It should >be assumed that by the time you get to the CCIE level you have much >experience in default routing. > First, ISP level engineers are going to configure default routes for customers, and, indeed, there often are default routes in POPs, or in smaller ISPs. Second, the combination of static default routes with multiple administrative distances can get quite complex. Third, I am more bothered by the lack of static routes than defaults. Complex static routes, with alternatives, are common for traffic engineering. Blackhole static routes are extensively used. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75193&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Reimer, Fred wrote: > > I've always liked hex myself. A hex mask of FF.FF.F8.00 can be > written as > F800 and still mean the same thing. You obviously can't do > that with > 255.255.128.0 (255.255.128.0 != 2,552,551,280). While binary > works the same > way as hex in this manner, it is much to long for my tastes. > Plus, hex is > used a lot in programming languages when using values in > bitmasks, so I'm > more familiar with it. Also, there are only 5 hex numbers that > you need to > memorize for masks, F 0 8 C and E. And binary is going to be pretty hard to deal with when we get to 128-bit IPv6 addresses!? Dotted decimal notation is really an awful thing. I agree with Howard that it confuses people and should be taught after the binary representation of addresses (and maybe hex?) Not only does dotted decimal notation confuse people with addresses, but it gets them thinking 8 bits at a time, when programming languages, protocol analyzers, debuggers, etc. think 4 bits at a time. Priscilla > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA > 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary > information which > may be legally privileged. It is intended only for the named > recipient(s). > If an addressing or transmission error has misdirected the > email, please > notify the author by replying to this message. If you are not > the named > recipient, you are not authorized to use, disclose, distribute, > copy, print > or rely on this email, and should immediately delete it from > your computer. > > > -Original Message- > From: Howard C. Berkowitz [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 11:32 PM > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > At 10:36 PM + 9/9/03, Dom wrote: > >Fred, check out the archives for Howard's piece on the > difference > >between 'Rocket Science' and 'BGP' when at NASA. > > > >Best regards, > > > >Dom Stocqueler > >SysDom Technologies > >Visit our website - www.sysdom.org > > > Seriously, I've fought a battle for many years with Cisco > Training. I > believe the fundamental problem they _create_ is insisting on > teaching classful and dotted decimal notation first. > > When I've given private classes -- ICRC, the older RSC, etc. -- > I > always began discussing addressing in binary, got people used > to the > idea of prefix length, then introduced dotted decimal as a > means of > representation, and then introduced classful addressing as a > historic > concept. Students were always able to go right into classless > routing without any trouble. > > There are some nice examples in RFC 1878. RFCs 1517-1520 give > the > main background, although there are some earlier papers on > "supernetting". > > With all mercenary disclaimers, I also recommend my book, > _Designing > Addressing Architectures for Routing and Switching_, and my > recent > IPv4/IPv6 tutorial on Certification Zone. > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75199&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
Funny thing about this is that most "experts" that I've dealt with working at major ISPs who do nothing but deal with BGP and routing daily still don't get the configurations right the first time. I've never had a BGP neighbor setup go smoothly (i.e. take less than 2 hours), and it was never a problem on my side of the configuration. So don't blame yourself if you don't get it right the first time. And don't be afraid of it... Most "experts", in my experiences, still make mistakes with BGP. -Original Message- From: Reimer, Fred [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 10, 2003 11:26 AM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] Yes! Even I would not feel comfortable configuring BGP in a production environment yet, and although I don't have my CCNP yet, I did pass the routing and switching tests. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 09, 2003 7:32 PM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] Dom wrote: > > And one last point, No LAN is an island, why two IG(P) > protocols and no > EG(P) protocol? > > A NA should at least a some understanding of how to connect to > the > outside world - when to use BGP and when not to. Default routing. Wouldn't we all be better off if CCNAs would stay away from BGP?? :-) Priscilla > > Sorry Fred, not having a go at you personally, but these are > points we > all need to think about. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > > -Original Message- > From: Dom [mailto:[EMAIL PROTECTED] > Sent: 09 September 2003 23:37 > To: 'Reimer, Fred'; '[EMAIL PROTECTED]' > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > Oh, and while I'm on the subject - why EIGRP? This is a > proprietary > Cisco Protocol. OK, I believe that Juniper may have implemented > it, but > to the best of my knowledge no one else has. > > Best regards, > > Dom Stocqueler > SysDom Technologies > Visit our website - www.sysdom.org > > -----Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of > Reimer, Fred > Sent: 09 September 2003 22:03 > To: [EMAIL PROTECTED] > Subject: RE: Please Help - CIDR - How the bits work [7:75050] > > > I guess my expectation and Cisco's, or at least their current > expectations as listed on their web site, don't match then. By > my > definition a beginner should know about CIDR, EIGRP, and OSPF. > It's not > like they are inherently difficult to understand. People tend > to make > it sound like rocket science or voodoo magic. It's just a > routing > protocol folks. > > Fred Reimer - CCNA > > > Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA > 30338 > Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 > > > NOTICE; This email contains confidential or proprietary > information > which may be legally privileged. It is intended only for the > named > recipient(s). If an addressing or transmission error has > misdirected the > email, please notify the author by replying to this message. If > you are > not the named recipient, you are not authorized to use, > disclose, > distribute, copy, print or rely on this email, and should > immediately > delete it from your computer. > > > -Original Message- > From: "Chuck Whose Road is Ever Shorter" > [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 09, 2003 3:56 PM > To: [EMAIL PROTECTED] > Subject: Re: Please Help - CIDR - How the bits work [7:75050] > > ""Reimer, Fred"" wrote in message > news:[EMAIL PROTECTED] > > May be I had advanced access to the new NA material then ;-) > In my > > view, > a > > NA should be able to handle basic RIP, OSPF, EIGRP in a small > to > > medium sized network. That would certainly include CIDR. A > NP, IMO, > > would be >
RE: Please Help - CIDR - How the bits work [7:75050]
I was more referring to "core" ISP routers than edge (and I've certainly never worked for an ISP before, so I'm going on my experience and knowledge of routing protocols to surmise [guess] at what would be reasonable or not). If you have ISP engineers configuring the "ISP" router that is at the customer premise, then yes I would concede that there are probably a lot of default static routes, if not being the majority. As far as non-default static routes with different AD's, then I would certainly agree with you. I've used them myself extensively in multiple customer WAN configurations. Fred Reimer - CCNA Eclipsys Corporation, 200 Ashford Center North, Atlanta, GA 30338 Phone: 404-847-5177 Cell: 770-490-3071 Pager: 888-260-2050 NOTICE; This email contains confidential or proprietary information which may be legally privileged. It is intended only for the named recipient(s). If an addressing or transmission error has misdirected the email, please notify the author by replying to this message. If you are not the named recipient, you are not authorized to use, disclose, distribute, copy, print or rely on this email, and should immediately delete it from your computer. -Original Message- From: Howard C. Berkowitz [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 10, 2003 12:57 PM To: [EMAIL PROTECTED] Subject: RE: Please Help - CIDR - How the bits work [7:75050] At 11:34 AM -0400 9/10/03, Reimer, Fred wrote: >Yes, but the CCIE labs are supposed to be for ISP level engineers, who >almost certainly won't be using default routes most of the time. It should >be assumed that by the time you get to the CCIE level you have much >experience in default routing. > First, ISP level engineers are going to configure default routes for customers, and, indeed, there often are default routes in POPs, or in smaller ISPs. Second, the combination of static default routes with multiple administrative distances can get quite complex. Third, I am more bothered by the lack of static routes than defaults. Complex static routes, with alternatives, are common for traffic engineering. Blackhole static routes are extensively used. **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75202&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
RE: Please Help - CIDR - How the bits work [7:75050]
At 5:32 PM + 9/10/03, Priscilla Oppenheimer wrote: >Reimer, Fred wrote: >> >> I've always liked hex myself. A hex mask of FF.FF.F8.00 can be >> written as >> F800 and still mean the same thing. You obviously can't do >> that with >> 255.255.128.0 (255.255.128.0 != 2,552,551,280). While binary >> works the same >> way as hex in this manner, it is much to long for my tastes. >> Plus, hex is >> used a lot in programming languages when using values in >> bitmasks, so I'm >> more familiar with it. Also, there are only 5 hex numbers that >> you need to >> memorize for masks, F 0 8 C and E. > >And binary is going to be pretty hard to deal with when we get to 128-bit >IPv6 addresses!? Indeed, hex is the IPv6 convention except for some special cases like embedded IPv4 addresses. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75203&t=75050 -- **Please support GroupStudy by purchasing from the GroupStudy Store: http://shop.groupstudy.com FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
