subnet mask question [7:35357]
We know that 127.0.0.1 is for loopback. If we need to assing a subnet mask for it, what the number should be. for Class A, the noraml subnet mask is 255.0.0.0 for Class B, the normail subnet mask is 255.255.0.0. 127 is not belong to Class A and B. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=35357t=35357 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: subnet mask question [7:35357]
If you look at 127.0.0.0 in binary, it's a class A. Simon Yang (ITeX) wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... We know that 127.0.0.1 is for loopback. If we need to assing a subnet mask for it, what the number should be. for Class A, the noraml subnet mask is 255.0.0.0 for Class B, the normail subnet mask is 255.255.0.0. 127 is not belong to Class A and B. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=35360t=35357 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Subnet Mask question [7:25694]
I didn't see this come through the list so I'm re-posting. -Original Message- From: R. Benjamin Kessler [mailto:[EMAIL PROTECTED]] Sent: Thursday, November 08, 2001 10:01 AM To: Cisco GroupStudy List Subject: RE: Subnet Mask question [7:25602] I'm assuming that you entered something like this in a router: ip route 63.182.182.182 255.0.0.0 where = an interface name or IP address of a neighboring router. If this is an accurate assumption when you do a show run you'll probably see the following instead: ip route 63.0.0.0 255.0.0.0 This would explain why you're sending these other packets to 63.x.x.x to la-la land. Do a trace and see where the packets are going to confirm what I'm saying. Note: On more recent versions of IOS the router will complain and tell you that you have an inconsistent address and mask. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Telemachus Luu Sent: Wednesday, November 07, 2001 3:37 PM To: [EMAIL PROTECTED] Subject: Subnet Mask question [7:25602] Hi, Can someone provide a good explanation to this? Imaginary IPs: Static host ip: 63.182.182.182 mask: 255.255.255.0 I accidently specified an incorrect mask of 255.0.0.0. However, I was still able to ping some sites out in the net but was unable to ping a host in the same class, eg. 63.221.133.4. 1. Why was I able to ping out even though the mask specified was incorrect? 2. Why was I unable to ping the host in the same class? thanks, Telemachus Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=25694t=25694 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Subnet Mask question [7:25602]
I'm assuming that you entered something like this in a router: ip route 63.182.182.182 255.0.0.0 where = an interface name or IP address of a neighboring router. If this is an accurate assumption when you do a show run you'll probably see the following instead: ip route 63.0.0.0 255.0.0.0 This would explain why you're sending these other packets to 63.x.x.x to la-la land. Do a trace and see where the packets are going to confirm what I'm saying. Note: On more recent versions of IOS the router will complain and tell you that you have an inconsistent address and mask. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Telemachus Luu Sent: Wednesday, November 07, 2001 3:37 PM To: [EMAIL PROTECTED] Subject: Subnet Mask question [7:25602] Hi, Can someone provide a good explanation to this? Imaginary IPs: Static host ip: 63.182.182.182 mask: 255.255.255.0 I accidently specified an incorrect mask of 255.0.0.0. However, I was still able to ping some sites out in the net but was unable to ping a host in the same class, eg. 63.221.133.4. 1. Why was I able to ping out even though the mask specified was incorrect? 2. Why was I unable to ping the host in the same class? thanks, Telemachus Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=25688t=25602 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Subnet mask question..
Default netmask for class B is 255.255.0.0 with 11 subnet mask you will have /27 ie 255.255.255.224 it's bit confusing though.. Nobody Keith Woodworth [EMAIL PROTECTED] wrote in article [EMAIL PROTECTED]... Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Subnet mask question..
This is a matter of how the question was phrased. If a class B address had 11 bits of subnetting, then the mask is 255.255.255.224. Why? Because a class B address has NO bits of subnetting to begin with. You take the binary, ..., and to that you add 11 bits, and you'll get: ...1110 or 255.255.255.224. Does this help? Craig At 08:47 AM 10/14/2000 +, you wrote: Default netmask for class B is 255.255.0.0 with 11 subnet mask you will have /27 ie 255.255.255.224 it's bit confusing though.. Nobody Keith Woodworth [EMAIL PROTECTED] wrote in article [EMAIL PROTECTED]... Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Subnet mask question..
Brian, I hate the way these tests word their questions sometimes. Why don't they just state the mask as it should be -contiguous bits left to right(except for wildcard masks ofcourse). If they are going to state the subnet portion is stealing 11 bits from the host portion of the address why don't they just state that. You are exactly right though a /11 subnet mask is 255.224.0.0 Don't let these silly tests screw you up. I think sometimes they try to impress a point and screw things up. I don't think Cisco is in the business to have you memorize wrong information. (If you know subnetting in the real world, you will pass their test questions regarding these issues ~~I would read Cisco's ACRC book and practice their examples, there is also a great section on 3com's website on subnetting I highly reccomend). There are 3 portions of the address (network,subnet,and host)and the subnet portion is using 11 host bits to subdivide this class b network. The subnet mask would be /27 or 255.255.255.224not /11. Brian At 08:47 AM 10/14/2000 +, you wrote: Default netmask for class B is 255.255.0.0 with 11 subnet mask you will have /27 ie 255.255.255.224 it's bit confusing though.. Nobody Keith Woodworth [EMAIL PROTECTED] wrote in article [EMAIL PROTECTED]... Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Subnet mask question..
I am not sure if Brian is talking about this http://www.3com.com/nsc/501302.html but it is worth the reading. It is by Chuck Semeria . (about 100 pages in pdf format accessible at bottom of html page) Daniel -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Brian Lodwick Sent: Saturday, October 14, 2000 9:31 AM To: [EMAIL PROTECTED] Subject: Re: Subnet mask question.. Brian, I hate the way these tests word their questions sometimes. Why don't they just state the mask as it should be -contiguous bits left to right(except for wildcard masks ofcourse). If they are going to state the subnet portion is stealing 11 bits from the host portion of the address why don't they just state that. You are exactly right though a /11 subnet mask is 255.224.0.0 Don't let these silly tests screw you up. I think sometimes they try to impress a point and screw things up. I don't think Cisco is in the business to have you memorize wrong information. (If you know subnetting in the real world, you will pass their test questions regarding these issues ~~I would read Cisco's ACRC book and practice their examples, there is also a great section on 3com's website on subnetting I highly reccomend). There are 3 portions of the address (network,subnet,and host)and the subnet portion is using 11 host bits to subdivide this class b network. The subnet mask would be /27 or 255.255.255.224not /11. Brian At 08:47 AM 10/14/2000 +, you wrote: Default netmask for class B is 255.255.0.0 with 11 subnet mask you will have /27 ie 255.255.255.224 it's bit confusing though.. Nobody Keith Woodworth [EMAIL PROTECTED] wrote in article [EMAIL PROTECTED]... Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Subnet mask question..
The easiest thing in the world to do is just memorize the subnet table. If you do this, then just write out the table when you sit down to take the test (before you start the test). This way, you're not wasting time figuring it out. It's right in front of you. The table is very easy to memorize and will come in handy for the rest of your career, not just in testing. here's the link: http://www.gdd.net/cisco/ Then just click on "Subnet Cheat Sheet" But I agree, the questions are a bit misleading sometimes. Happy testing! - Original Message - From: Brian Lodwick [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Saturday, October 14, 2000 11:31 AM Subject: Re: Subnet mask question.. Brian, I hate the way these tests word their questions sometimes. Why don't they just state the mask as it should be -contiguous bits left to right(except for wildcard masks ofcourse). If they are going to state the subnet portion is stealing 11 bits from the host portion of the address why don't they just state that. You are exactly right though a /11 subnet mask is 255.224.0.0 Don't let these silly tests screw you up. I think sometimes they try to impress a point and screw things up. I don't think Cisco is in the business to have you memorize wrong information. (If you know subnetting in the real world, you will pass their test questions regarding these issues ~~I would read Cisco's ACRC book and practice their examples, there is also a great section on 3com's website on subnetting I highly reccomend). There are 3 portions of the address (network,subnet,and host)and the subnet portion is using 11 host bits to subdivide this class b network. The subnet mask would be /27 or 255.255.255.224not /11. Brian At 08:47 AM 10/14/2000 +, you wrote: Default netmask for class B is 255.255.0.0 with 11 subnet mask you will have /27 ie 255.255.255.224 it's bit confusing though.. Nobody Keith Woodworth [EMAIL PROTECTED] wrote in article [EMAIL PROTECTED]... Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Subnet mask question..
Well 11 bits of subnetting is : 255.255.255.224 Class B subnet is always 255.255.x.x so 11 bits of subnetting means after the first 2 255's you got 11 bits of subnetting. Wich is another 255 and then 3 bits of the host adress wich comes to 224. So there you got your 255.255.255.224 subnet mask. So your addresses can be : 172.16.3.33 to 172.16.3.62 ! Your first address starts with 32 .. but thats the network address so cant be used .. so 33 is the first you can use. Your next subnet starts with 64 .. So 63 will be your last host you can use. But in this case 63 is your broadcast address. So 62 is the last host you can use ! Hope this solves it for you :) JT. -Original Message- From: Keith Woodworth [mailto:[EMAIL PROTECTED]] Sent: dinsdag 10 oktober 2000 7:07 To: [EMAIL PROTECTED] Subject: Subnet mask question.. Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask Thanks for clue. Keith **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Subnet mask question..
On Tue, 10 Oct 2000, Jeroen Timmer wrote: Well 11 bits of subnetting is : 255.255.255.224 Class B subnet is always 255.255.x.x so 11 bits of subnetting means after the first 2 255's you got 11 bits of subnetting. Wich is another 255 and then 3 bits of the host adress wich comes to 224. So there you got your 255.255.255.224 subnet mask. So your addresses can be : 172.16.3.33 to 172.16.3.62 ! Your first address starts with 32 .. but thats the network address so cant be used .. so 33 is the first you can use. Your next subnet starts with 64 .. So 63 will be your last host you can use. But in this case 63 is your broadcast address. So 62 is the last host you can use ! Yes I think I pretty much understand subnetting it was the wording of the question that threw me off...way off. I will be carefull with the wording of questions now. Another block is in place. Thanks, Keith **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Subnet mask question..
I thought that was strange when I first saw a question like that. Oh Well, Cisco does things there own way. Neil Schneider "Keith Woodworth" [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask Thanks for clue. Keith **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Subnet mask question..
The answer is in the question. They say an 11 bit SUBNET MASK. So the natural mask is as you say class B which = 255.255.0.0 hence you then have an eleven bit SUBNET mask. Which is 255.255.255.224 as you say. Tricky questions put in there to catch you out. -Original Message- From: Neil Schneider [mailto:[EMAIL PROTECTED]] Sent: 10 October 2000 13:18 To: [EMAIL PROTECTED] Subject: Re: Subnet mask question.. I thought that was strange when I first saw a question like that. Oh Well, Cisco does things there own way. Neil Schneider "Keith Woodworth" [EMAIL PROTECTED] wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask Thanks for clue. Keith **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Subnet mask question..
Ive been at this for quite a while and the odd subnet question still gets me. Boson question: IP address 172.16.3.57 w/ and 11-bit subnet mask. What are valid hosts? I think ok class B, but I look at 11 bits as 255.224.0.0 (.1110.0.0) which does not go with the choices of answers I had. I got it wrong as the answer says an 11-bit mask is 255.255.255.224 when using a class b address. Is the mask there not 27 bits? What am I missing there? How do they get the above mask w/11 bits? The valid hosts were: 172.16.3.33-172.16.3.62, which I think is valid for a 27 bit mask Thanks for clue. Keith **NOTE: New CCNA/CCDA List has been formed. For more information go to http://www.groupstudy.com/list/Associates.html _ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Newbe -- Subnet mask question
You kind of answer your own question. Since you understand how many subnets and hosts there are in both questions, the answer is that's why the number is there - to split the one class C network up into several subnets with fewer hosts. Hth, Ole ~~ Ole Drews Jensen Systems Network Manager CCNA, MCSE, MCP+I RWR Enterprises, Inc. [EMAIL PROTECTED] ~~ -Original Message- From: Dick Silva [mailto:[EMAIL PROTECTED]] Sent: Friday, July 07, 2000 11:12 PM To: [EMAIL PROTECTED] Subject: Newbe -- Subnet mask question Group -- Some enlightenment is appreciated. The following two examples are directly from Todd Lammle's CCNA book, 2nd edition. Pages 140 and 141. 1st example: Given a network address of:192.168.10.0 Given a subnet mask: 255.255.255.192 Where does this 192 come from? I understand that 192 = 1100 And I understand that there are 2 subnets and 62 hosts and how to calculate both of these values. I would just like to know where the 192 comes from and some explanation of its purpose. 2nd example: Given the same network address: 192.168.10.0 Given the subnet mask: 255.255.255.224 So where does the 224 come from? I understand that 224 = 1110 And that there are 6 subnets and 30 hosts. Again where does the value 224 come from and its purpose. What determines the selection of these two, 192 and 224, values or any of the others that are plugged in. I am not talking about the 255 values. Those I understand,. Constructive feedback would be genuinely appreciated. [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Newbe -- Subnet mask question
These numbers are the decimal version of their binary equivalents. The binary bit positions have the following values, from left to right: 128,64,32,16,8,4,2, and 1. You can determine the decimal equivalent of a binary number by adding up the values for the bit positions. 255 (decimal) = (binary) 224 = 1110 192 = 1100 I hope this makes sense. It's very late and I've been working on a resume. You know how annoying THAT can be! :-) John Neiberger Group -- Some enlightenment is appreciated. The following two examples are directly from Todd Lammle's CCNA book, 2nd edition. Pages 140 and 141. 1st example: Given a network address of:192.168.10.0 Given a subnet mask: 255.255.255.192 Where does this 192 come from? I understand that 192 = 1100 And I understand that there are 2 subnets and 62 hosts and how to calculate both of these values. I would just like to know where the 192 comes from and some explanation of its purpose. 2nd example: Given the same network address: 192.168.10.0 Given the subnet mask: 255.255.255.224 So where does the 224 come from? I understand that 224 = 1110 And that there are 6 subnets and 30 hosts. Again where does the value 224 come from and its purpose. What determines the selection of these two, 192 and 224, values or any of the others that are plugged in. I am not talking about the 255 values. Those I understand,. Constructive feedback would be genuinely appreciated. [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ Say Bye to Slow Internet! http://www.home.com/xinbox/signup.html ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Newbe -- Subnet mask question
192=128 + 64 (1 1 0 0 0 0 0 0) 224=128 + 64 + 32 (1 1 1 0 0 0 0 0) In both the high order bits are added. Hope that helps makeeda -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Dick Silva Sent: Saturday, July 08, 2000 12:12 AM To: [EMAIL PROTECTED] Subject: Newbe -- Subnet mask question Group -- Some enlightenment is appreciated. The following two examples are directly from Todd Lammle's CCNA book, 2nd edition. Pages 140 and 141. 1st example: Given a network address of:192.168.10.0 Given a subnet mask: 255.255.255.192 Where does this 192 come from? I understand that 192 = 1100 And I understand that there are 2 subnets and 62 hosts and how to calculate both of these values. I would just like to know where the 192 comes from and some explanation of its purpose. 2nd example: Given the same network address: 192.168.10.0 Given the subnet mask: 255.255.255.224 So where does the 224 come from? I understand that 224 = 1110 And that there are 6 subnets and 30 hosts. Again where does the value 224 come from and its purpose. What determines the selection of these two, 192 and 224, values or any of the others that are plugged in. I am not talking about the 255 values. Those I understand,. Constructive feedback would be genuinely appreciated. [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Newbe -- Subnet mask question
The 192 comes from the admin. If you were the admin of a network, and maybe you are, you would probably get a full class 'C' (255.255.255.0) from your ISP or maybe ARIN. You would decide how you want to divide that network. If you wanted to divide it into two parts you would extend your mask by one bit or 255.255.255.128. If you wanted to divide it into four parts you would exetend it to 255.255.255.192. You supplied the .192. The 255.255.255.0 you get from ARIN. You make the decision if you want to change it and how much. Lamle is pulling the .192 out of the air and giving it to you for example purposes. Earl Aboytes Senior Technical Consultant GTE Managed Solutions Dick Silva wrote: Group -- Some enlightenment is appreciated. The following two examples are directly from Todd Lammle's CCNA book, 2nd edition. Pages 140 and 141. 1st example: Given a network address of:192.168.10.0 Given a subnet mask: 255.255.255.192 Where does this 192 come from? I understand that 192 = 1100 And I understand that there are 2 subnets and 62 hosts and how to calculate both of these values. I would just like to know where the 192 comes from and some explanation of its purpose. 2nd example: Given the same network address: 192.168.10.0 Given the subnet mask: 255.255.255.224 So where does the 224 come from? I understand that 224 = 1110 And that there are 6 subnets and 30 hosts. Again where does the value 224 come from and its purpose. What determines the selection of these two, 192 and 224, values or any of the others that are plugged in. I am not talking about the 255 values. Those I understand,. Constructive feedback would be genuinely appreciated. [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Newbe -- Subnet mask question
Group -- Some enlightenment is appreciated. The following two examples are directly from Todd Lammle's CCNA book, 2nd edition. Pages 140 and 141. 1st example: Given a network address of:192.168.10.0 Given a subnet mask: 255.255.255.192 Where does this 192 come from? I understand that 192 = 1100 And I understand that there are 2 subnets and 62 hosts and how to calculate both of these values. I would just like to know where the 192 comes from and some explanation of its purpose. 2nd example: Given the same network address: 192.168.10.0 Given the subnet mask: 255.255.255.224 So where does the 224 come from? I understand that 224 = 1110 And that there are 6 subnets and 30 hosts. Again where does the value 224 come from and its purpose. What determines the selection of these two, 192 and 224, values or any of the others that are plugged in. I am not talking about the 255 values. Those I understand,. Constructive feedback would be genuinely appreciated. [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Newbe -- Subnet mask question
On Sat, 8 Jul 2000, Dick Silva wrote: Group -- Some enlightenment is appreciated. The following two examples are directly from Todd Lammle's CCNA book, 2nd edition. Pages 140 and 141. 1st example: Given a network address of:192.168.10.0 Given a subnet mask: 255.255.255.192 Where does this 192 come from? I understand that 192 = 1100 That's where it comes from. Think of it as starting in binary, and being represented as 192 decimal. And I understand that there are 2 subnets and 62 hosts and how to calculate both of these values. I would just like to know where the 192 comes from and some explanation of its purpose. Look at the entire subnet mask: 1100 255 255 255 192 The 1 bits represent the portion of the address that defines the network. The 0 bits represent hosts on the network. Note that the mask of 26 contiguous 1 bits can also be shown as a /26 after the address, so the network and mask can also be written 192.168.10.0/26 Applying that mask to your network address, we see that for a host to be contained in the local subnet, it must match 1100 10101000 1010 00-- If the first 26 bits of the address match this pattern, then the address matches the mask, and is part of the local subnet. Addresses from 192.168.10.0 through 192.168.10.63 match. But, if we look at the address 192.168.10.64 in binary, we see: 1100 10101000 1010 0100 ^ Note that the 1 bit in the last octet causes a change in the network part of the address as defined by the mask. A host or router uses the network mask to determine if an address is on the local subnet or not. In this case, traffic to 192.168.10.0 through 192.168.10.63 (yes, the first and last addresses are special, but ignore that for now) matches the netmask, and is local, so send directly to the destination. Traffic not matching the mask, such as 192.168.10.64 (or any other address not within the range of .0 through .63) must be routed. In the case of a simple host, it will have an address, netmask, and default gateway. The netmask determines which addresses are simply put on the local wire, and which are forwarded to the gateway for routing to the destination. 2nd example: Given the same network address: 192.168.10.0 Given the subnet mask: 255.255.255.224 So where does the 224 come from? I understand that 224 = 1110 And that there are 6 subnets and 30 hosts. Again where does the value 224 come from and its purpose. Again, it's the decimal representation of 1110, with the previous octets each eight 1s, that's 27 contiguous 1s in the mask. So now, any addresses that don't have the first 27 bits identical to the host address will not be on the local network. This network may also be represented 192.168.10.0/27 (denoting the 27 bits in the mask). What determines the selection of these two, 192 and 224, values or any of the others that are plugged in. I am not talking about the 255 values. Those I understand,. Constructive feedback would be genuinely appreciated. The numbers simply represent those binary values which happen to have a string of 1 bits followed by a string of 0 bits. A network mask will have 1s for the network portion and 0s for the host portion. Sane networks use the higher bits to represent the network and lower bits to represent the host, so a binary network mask will be a string of 1s followed by a string of 0s. So, you'll see 255 = 254 = 1110 252 = 1100 248 = 1000 240 = 224 = 1110 192 = 1100 128 = 1000 0 = in various places in netmasks. Octets, if any to the left of these will be 255, and any to the right will be 0, ensuring 1s in the network portion and 0s in the host portion. Also note that both of the networks shown would not be legal in the classful, no subnet-zero method of thinking that is taught early on in CCNA. Don't sweat this for now unless you've passed CCNA. These networks can be used with some tricks you'll learn in the future. -- Jay Hennigan - Network Administration - [EMAIL PROTECTED] NetLojix Communications, Inc. NASDAQ: NETX - http://www.netlojix.com/ WestNet: Connecting you to the planet. 805 884-6323 ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
