At 10:36 PM +0000 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 >> >> >> 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 > > >> > >> > -----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 VEEEEEERY 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 Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=75151&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
