Re: Re: Summarization?? What's that? (bug report) [7:37096]
Just for grins, I tried to find out what summary-address does under BGP in 11.2 but I wasn't able to find a reference for it. The 11.2 Command Reference says that command is only for OSPF and IS-IS, which is what I expected. Still, it's interesting that the router let me make this particular mistake in the BGP config. Oh well, like I said, time to go to bed. I'll sleep off my embarrassment. :-) John On Sun, 3 Mar 2002, John Neiberger ([EMAIL PROTECTED]) wrote: > oopsWhat the heck was I thinking?? That's a sure sign I've > been studying too long today. I know very well the difference > between summary-address and aggregate-address and I still was > using the wrong command! Good grief... > > And even while I was typing my first post I had this nagging > feeling that I was overlooking something. :-) Maybe I should > have tried using the BGP area range command. heh heh... > > I think I didn't catch my mistake because another router > running 11.2(25a) accepted the command. Now I'm interested to > find out what that particular command is doing. > > This is actually one of my biggest worries when I get to the > actual lab. I fear that stuff I've done over and over again > will completely slip my mind. > > Okay, I'm done for the night! > > Thanks, > John > > On Sun, 3 Mar 2002, Nigel Taylor > ([EMAIL PROTECTED]) wrote: > > > John, > > You might want to try using the aggregate-address > command and > > see > > what magic happens. As a side note.. IGP's summarize, > whereas BGP being > > an > > EGP aggregates. > > > > watch the word wrap.. > > > > > http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/ > 122cgcr/fipr > > rp_r/bgp_r/1rfbgp1.htm#xtocid1 > > > > Nigel > > > > - Original Message - > > From: "John Neiberger" > > To: > > Sent: Sunday, March 03, 2002 12:30 AM > > Subject: Summarization?? What's that? (bug report) > > > > > > > While attempting to summarize some prefixes in BGP I got the > > > following: > > > > > > R3#conf t > > > Enter configuration commands, one per line. End with > CNTL/Z. > > > R3(config)#router bgp 2010 > > > R3(config-router)#summa? > > > % Unrecognized command > > > R3(config-router)#summar? > > > % Unrecognized command > > > R3(config-router)#summar > > >^ > > > % Invalid input detected at '^' marker. > > > > > > R3(config-router)#? > > > Router configuration commands: > > > address-family Enter Address Family command mode > > > aggregate-addressConfigure BGP aggregate entries > > > auto-summary Enable automatic network number > > > summarization > > > bgp BGP specific commands > > > default Set a command to its defaults > > > default-information Control distribution of default > > > information > > > default-metric Set metric of redistributed routes > > > distance Define an administrative distance > > > distribute-list Filter networks in routing updates > > > exit Exit from routing protocol > configuration > > > mode > > > help Description of the interactive help > > > system > > > maximum-pathsForward packets over multiple paths > > > neighbor Specify a neighbor router > > > network Specify a network to announce via BGP > > > no Negate a command or set its defaults > > > redistribute Redistribute information from another > > > routing protocol > > > synchronization Perform IGP synchronization > > > table-mapMap external entry attributes into > > > routing table > > > timers Adjust routing timers > > > > > > R3(config-router)# > > > > > > I'm thinking it might be tough to do summarization when the > > > freaking command is missing!! > > > > > > This is a 2500 running 12.1(11) Enterprise Plus. Too > weird. I > > > didn't find a bug report for it on CCO but I can't be the > only > > > person to run into this. > > > > > > Since I don't feel like doing un upgrade right now, I'll > skip > > > that part. > > > > > > John > > > > > _ > > > Commercial lab list: > http://www.groupstudy.com/list/commercial.html > > > Please discuss commercial lab solutions on this list. > > > > > _ > Commercial lab list: http://www.groupstudy.com/list/commercial.html > Please discuss commercial lab solutions on this list. > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37096&t=37096 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violati
Re: Re: Summarization?? What's that? (bug report) [7:37094]
oopsWhat the heck was I thinking?? That's a sure sign I've been studying too long today. I know very well the difference between summary-address and aggregate-address and I still was using the wrong command! Good grief... And even while I was typing my first post I had this nagging feeling that I was overlooking something. :-) Maybe I should have tried using the BGP area range command. heh heh... I think I didn't catch my mistake because another router running 11.2(25a) accepted the command. Now I'm interested to find out what that particular command is doing. This is actually one of my biggest worries when I get to the actual lab. I fear that stuff I've done over and over again will completely slip my mind. Okay, I'm done for the night! Thanks, John On Sun, 3 Mar 2002, Nigel Taylor ([EMAIL PROTECTED]) wrote: > John, > You might want to try using the aggregate-address command and > see > what magic happens. As a side note.. IGP's summarize, whereas BGP being > an > EGP aggregates. > > watch the word wrap.. > > http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/ 122cgcr/fipr > rp_r/bgp_r/1rfbgp1.htm#xtocid1 > > Nigel > > - Original Message - > From: "John Neiberger" > To: > Sent: Sunday, March 03, 2002 12:30 AM > Subject: Summarization?? What's that? (bug report) > > > > While attempting to summarize some prefixes in BGP I got the > > following: > > > > R3#conf t > > Enter configuration commands, one per line. End with CNTL/Z. > > R3(config)#router bgp 2010 > > R3(config-router)#summa? > > % Unrecognized command > > R3(config-router)#summar? > > % Unrecognized command > > R3(config-router)#summar > >^ > > % Invalid input detected at '^' marker. > > > > R3(config-router)#? > > Router configuration commands: > > address-family Enter Address Family command mode > > aggregate-addressConfigure BGP aggregate entries > > auto-summary Enable automatic network number > > summarization > > bgp BGP specific commands > > default Set a command to its defaults > > default-information Control distribution of default > > information > > default-metric Set metric of redistributed routes > > distance Define an administrative distance > > distribute-list Filter networks in routing updates > > exit Exit from routing protocol configuration > > mode > > help Description of the interactive help > > system > > maximum-pathsForward packets over multiple paths > > neighbor Specify a neighbor router > > network Specify a network to announce via BGP > > no Negate a command or set its defaults > > redistribute Redistribute information from another > > routing protocol > > synchronization Perform IGP synchronization > > table-mapMap external entry attributes into > > routing table > > timers Adjust routing timers > > > > R3(config-router)# > > > > I'm thinking it might be tough to do summarization when the > > freaking command is missing!! > > > > This is a 2500 running 12.1(11) Enterprise Plus. Too weird. I > > didn't find a bug report for it on CCO but I can't be the only > > person to run into this. > > > > Since I don't feel like doing un upgrade right now, I'll skip > > that part. > > > > John > > _ > > Commercial lab list: http://www.groupstudy.com/list/commercial.html > > Please discuss commercial lab solutions on this list. > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37094&t=37094 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization?? What's that? (bug report) [7:37093]
John, You might want to try using the aggregate-address command and see what magic happens. As a side note.. IGP's summarize, whereas BGP being an EGP aggregates. watch the word wrap.. http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr rp_r/bgp_r/1rfbgp1.htm#xtocid1 Nigel - Original Message - From: "John Neiberger" To: Sent: Sunday, March 03, 2002 12:30 AM Subject: Summarization?? What's that? (bug report) > While attempting to summarize some prefixes in BGP I got the > following: > > R3#conf t > Enter configuration commands, one per line. End with CNTL/Z. > R3(config)#router bgp 2010 > R3(config-router)#summa? > % Unrecognized command > R3(config-router)#summar? > % Unrecognized command > R3(config-router)#summar >^ > % Invalid input detected at '^' marker. > > R3(config-router)#? > Router configuration commands: > address-family Enter Address Family command mode > aggregate-addressConfigure BGP aggregate entries > auto-summary Enable automatic network number > summarization > bgp BGP specific commands > default Set a command to its defaults > default-information Control distribution of default > information > default-metric Set metric of redistributed routes > distance Define an administrative distance > distribute-list Filter networks in routing updates > exit Exit from routing protocol configuration > mode > help Description of the interactive help > system > maximum-pathsForward packets over multiple paths > neighbor Specify a neighbor router > network Specify a network to announce via BGP > no Negate a command or set its defaults > redistribute Redistribute information from another > routing protocol > synchronization Perform IGP synchronization > table-mapMap external entry attributes into > routing table > timers Adjust routing timers > > R3(config-router)# > > I'm thinking it might be tough to do summarization when the > freaking command is missing!! > > This is a 2500 running 12.1(11) Enterprise Plus. Too weird. I > didn't find a bug report for it on CCO but I can't be the only > person to run into this. > > Since I don't feel like doing un upgrade right now, I'll skip > that part. > > John > _ > Commercial lab list: http://www.groupstudy.com/list/commercial.html > Please discuss commercial lab solutions on this list. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=37093&t=37093 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Summarization [7:32035]
David, Another thing that I wonder about is the remote end; what do those routers look like? If you have something like this: +-Hub1---Hub3-+ | \ / | RemoteX-+ X +-RemoteY | / \ | +-Hub2---Hub4-+ You'll probably want to restrict what routes the remote routers can advertise. Given the size of your network, it would seem to me that something similar to the following would be more appropriate (disclaimer here, I know nothing of your business requirements nor am I looking at $$ as a limiting factor - which I'm certain it is). I'm making these basic assessments off the fact that your network doesn't seem to follow the standard Cisco Core-Distribution-Access model (yes, I've probably consumed too much of the Cisco Kool-Aid). +-Distr1---Hub1---Hub3---Distr3-+ | |\ /\ /\ /| | RegionA-+ | X X X | +-RegionZ | |/ \/ \/ \| | +-Distr2---Hub2---Hub4---Distr4-+ Within each region you'd have a contiguous block of addresses (both WAN and LAN segments) you then summarize from the distribution-layer routers to the hubs. The hub forward these summary routes to the other hub routers and so on until they reach the remote routers in the other regions. Again, I don't know the requirements of your network but if I were starting with a clean sheet of paper and we wanted to use RFC1918 addresses, I'd probably consider using the 172.x.x.x space. Each region could be a separate /16. If we define the core as the including all of the hub routers as well as the networks connecting them to the various distribution routers and make that the network 172.16.0.0/16 (obviously, there are multiple subnets needed, but they'd all be summarizable in this "major" net). Then assign a /16 to each region - so RegionA would be 172.17.0.0/16, RegionB would be 172.18.0.0/16, etc. Assuming that you have a data center or two, the server farms in these locations would also connect to the hub routers (ideally behind their own distribution-layer routers which summarize the address space for the server farms into the core). Generally speaking, a design like this will scale into the thousands of sites - obviously YMMV depending on your requirements. The key rule to follow here is that the core of the network is optimized to route packets. This is not the place to enforce network policy (ACLs, QOS, manual summarization, etc.). We all love the network 10.0.0.0/8; it gives us great freedom and allows networks to be built without concern for addressing efficiency. There are some downsides to this though and you've found one. You've been dealt a slightly worse hand though because you sandwich 172.x.x.x networks between 10.x.x.x. I'm going to go out on a limb (kidding) and suggest that your EIGRP configurations have "no auto-summary" configured, right? In the configuration above, you could allow EIGRP to auto-summarize - you'd actually prefer it because it would mean that you didn't need to manually summarize at all. There are some things you can do to probably make your existing hardware investment work with the current number of sites but it will require that you re-address your network to follow something similar to the design I outlined above just without the separate distribution routers. If you're growing like mad you'll want to ensure that you can get funding for the distribution layer because at some point (if not already) you'll have too many neighbors on each core router which will spark a whole new set of problems. Quickly, on the remote routers, I don't care how big or small the network is, in a (highly) redundant network I try to make sure that each router only advertises networks it's responsible for (e.g. directly connected or down-stream subnets). With EIGRP one of the easiest ways to do this is with the distribute-list command. I try to select a standard ACL number (for example # 5) across the enterprise and then on each router permit only the networks we want - in this case, the remote routers would advertise their directly-connected Ethernet network(s) and maybe a loopback. This will keep EIGRP from thinking that the remote router is a possible transit path to all other networks (especially a problem if you use sub-interfaces on the remote side). Well, I could go on and on but I've got to get back to studying. These are just some suggestions that have worked for me in the past, I'd be interested in what others on the list have experienced. Hope this helps, Ben -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Tuesday, January 15, 2002 5:51 AM To: [EMAIL PROTECTED] Subject: RE:Summarization (to Ben Kessler) [7:31975] Ben, I'm afraid that when I answered your post it was already buried under tons of other post. I'm sorry, these are the consequences of living in Europe...:-> Anyway, thanks for your detailed answer, I hope to get more det
RE: Summarization [7:31766]
Hello Ben, thanks for your detailed answer. I'm afraid I have no idea what happened but I'm think that it wasn't a problem with CPU unless summarization is a very intensive cpu process(I don't know if it is). We have a hub-and-spoke topology. Four 7500 (2 7513 and 2 7507) for backbone (ATM)and over 230 sites (2500 an 2600 mainly), and we have implemented redundancy using dialers and ISDN connections (and yes, we have conected each router to two different hub routers). In one of the 7513 we have over 100 dialers and 90 serial WANs connections, I have tried the summarization again with only two routers and by now, I haven't experimented any problem. As you can guess, our network is growing more and more and I'm worried about routing tables with a lot of entries (we're using network 172.x.x.x for serial interfaces and 10.x.x.x for ethernet interfaces) I tried to summarize on networks 10.x.x.x and 172.x.x.x using the following commands ip summary-address eigrp 1 10.0.0.0 255.0.0.0 ip summary-address eigrp 1 172.0.0.0 255.0.0.0 Today, I have talked with my boss and we've decided to try the summarization again but we're going to use the 0.0.0.0 network instead the other two (I'll try to check my RSP in-depth this time) Anyway, we're not experts in Cisco so I thought that we could reduce routing tables using summary address and make easier the administration and troubleshooting (perhaps it isn't a good idea). Unfortunatly, we work in a helth-care enviroment, and we have to make sure before doing anything in backbone routers. I hope you read this post, I live in Europe and every time I have to reply a post I have hundreds before me. Anyway, I'll keep you and this wonderful group informed. David Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=31888&t=31766 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Summarization [7:31766]
I've done it with about 100 interfaces on 7513's and didn't see this problem. It may be a limitation of the code on the box, memory (as you indicated), or something else. Have you been able to rule-out as many "something elses" as possible? What does the network topology look like? Do you have redundancy in place - e.g. spoke routers connected to two different hub routers? Are you getting a lot of SIAs? Routes flapping, etc.? How's the CPU on your RSP's looking? Free memory? Buffer misses? There's a common view that EIGRP works fine and can scale infinitely big without going through all of the steps that you'd have to go through for a large-scale OSPF installation. Obviously, this thought is very wrong. I'm guessing that you need to do manual summarization on 200 interfaces per box is because you don't have clearly-defined summarization points in the network - that's the situation I was in when I had to do it on ~100 interfaces. For good or ill, EIGRP will work with a bad network design (I'm speaking from an ideal perspective - please don't be offended, we all have to things at one time or another that are considered "bad") up until a point. Beyond that point, it gets really ugly - quickly. In the network I was working on we had 140 sites connected without problems. We started adding more offices and by the time we hit 170 the network was totally unstable. After several weeks of P1/CAP cases we met with the guys who write the code and found out what we were doing wrong - they have since published several CiscoPress books on EIGRP; none existed four years ago :) You can "band-aid" a broken network by using a lot of the EIGRP features (manual summarization, distribute-lists, etc.). In my case that's exactly what we did, unfortunately, I was not given the opportunity to correct the mistakes that required the band-aids. I have since moved on to new challenges but that network is still in the same state - four years later. Anyhow, if you can offer more specifics, I'm sure those of us on the list would be happy to comment and offer suggestions. I think that if we can solve the reason you need to manually summarize on 200 interfaces you'll be better off down the road. Ben -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Sunday, January 13, 2002 5:02 AM To: [EMAIL PROTECTED] Subject: Summarization [7:31766] Hello folks, I'm working in a EIGRP enviroment, and I have some questions for you: Has anyone tried to do a manual route sumarization per interface with more or less 200 interfaces in a 7500? I've tried but I'm having a few problems, the summary routes aren't advertised sufficiently fast to the routers in branch offices. The summary routes are sometimes marked as "possibly down" in the routers of branch offices, sometimes are up and sometimes are down. Do you know any relationship between memory or cpu (or whatever) of the 7500 and number of interfaces in which you can perform manual summarization? David Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=31787&t=31766 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization
Hi 128.213.64.0 - 128.213.95.0 => 32 /24 ip addresses the mask you supplied 255.255.192.0 includes 64 /24 ip addresses. So, the right mask is 255.255.224.0 Note that you should have ip classless specified on your router. Hope the explanation helps. Geoff - Original Message - From: archstein To: [EMAIL PROTECTED] Sent: Tuesday, November 14, 2000 5:27 AM Subject: Summarization Hi groups... Can you help me please ? What is summary address for subnet 128.213.64.0 - 128.213.95.0 ? Is that right if the summary address is 128.213.64.0 255.255.192.0 To determine ther sumary route, the router looks for the most highest-order number of bits that match. If there is no match bits, how to summarize ??? Thanks
Re: Summarization
Te summary route would be 128.213.64.0 255.255.224.0 64: 010 0 95: 010 1 - 224: 111 0 ALI SHEERAZ >From: "archstein" <[EMAIL PROTECTED]> >Reply-To: "archstein" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Subject: Summarization >Date: Tue, 14 Nov 2000 11:27:56 +0700 > > >Hi groups... > >Can you help me please ? What is summary address for subnet 128.213.64.0 >- 128.213.95.0 ? >Is that right if the summary address is 128.213.64.0 255.255.192.0 >To determine ther sumary route, the router looks for the most highest-order >number of bits that match. >If there is no match bits, how to summarize ??? >Thanks > _ 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: Summarization
before the flames start, let me correct myself :) On Mon, 13 Nov 2000, Brian wrote: > On Tue, 14 Nov 2000, archstein wrote: > > > > > Hi groups... > > > > Can you help me please ? What is summary address for subnet 128.213.64.0 - >128.213.95.0 ? > > 128.213.64.0/27 would summarize that range. > 129.213.64.0/19 > > Is that right if the summary address is 128.213.64.0 255.255.192.0 > > thats 128.213.64.0/26, and it summarizes 128.213.64.0 - 128.213.127.255 128.213.64.0/18 I have this bad habit of thinking in the ranges of /32-/24.working for an ISP, thats what I am constantly allocating. When I see "64-96"./27 instantly pops into my head, and then I post haphazardly.disregard my ramblings late into the night...after 10pm I am so burnt out from sitting in front of routers, I am not good and start to break down :). Brian > > > To determine ther sumary route, the router looks for the most highest-order number >of bits that match. > > If there is no match bits, how to summarize ??? > > well, sometimes you can't. > > Brian > > > > Thanks > > > > > > --- > Brian Feeny, CCNP, CCDP [EMAIL PROTECTED] > Network Administrator > ShreveNet Inc. (ASN 11881) > > --- Brian Feeny, CCNP, CCDP [EMAIL PROTECTED] Network Administrator ShreveNet Inc. (ASN 11881) _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Summarization
I think the subnet mask should be 255.255.224.0 126.213.64.0 = 0100 128.213.95.0 = 0101 subnetmask = 1110 = 224 raymond. -Original Message-From: Chuck Larrieu [mailto:[EMAIL PROTECTED]]Sent: 14 Nopember 2000 13:11To: archstein; [EMAIL PROTECTED]Subject: RE: Summarization 126.213.64.0 = 0100 .0 126.213.95.0 = 0111 .0 subnet mask = 1100 .0 = ? do you see it? the summarization boundary occurs at the last point to the left where all bits in both rows are the same. in your example, that is at the point between the 64 and the 32 position. or at the 64 position, to be precise. I'm not sure I understand the second part of your question. Routers don't necessarily summarize on their own. they work only with what they are given via the configurations you enter. Every ip address has a host portion and a network portion. the network portion is determined by the mask you apply. network determination is made through a simple ( to a computer ) boolean XOR operation. the computer could care less where the network bits begin and end. Chuck -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of archsteinSent: Monday, November 13, 2000 8:28 PMTo: [EMAIL PROTECTED]Subject: Summarization Hi groups... Can you help me please ? What is summary address for subnet 128.213.64.0 - 128.213.95.0 ? Is that right if the summary address is 128.213.64.0 255.255.192.0 To determine ther sumary route, the router looks for the most highest-order number of bits that match. If there is no match bits, how to summarize ??? Thanks
Re: Summarization
On Tue, 14 Nov 2000, archstein wrote: > > Hi groups... > > Can you help me please ? What is summary address for subnet 128.213.64.0 - >128.213.95.0 ? 128.213.64.0/27 would summarize that range. > Is that right if the summary address is 128.213.64.0 255.255.192.0 thats 128.213.64.0/26, and it summarizes 128.213.64.0 - 128.213.127.255 > To determine ther sumary route, the router looks for the most highest-order number >of bits that match. > If there is no match bits, how to summarize ??? well, sometimes you can't. Brian > Thanks > > --- Brian Feeny, CCNP, CCDP [EMAIL PROTECTED] Network Administrator ShreveNet Inc. (ASN 11881) _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Summarization
126.213.64.0 = 0100 .0 126.213.95.0 = 0111 .0 subnet mask = 1100 .0 = ? do you see it? the summarization boundary occurs at the last point to the left where all bits in both rows are the same. in your example, that is at the point between the 64 and the 32 position. or at the 64 position, to be precise. I'm not sure I understand the second part of your question. Routers don't necessarily summarize on their own. they work only with what they are given via the configurations you enter. Every ip address has a host portion and a network portion. the network portion is determined by the mask you apply. network determination is made through a simple ( to a computer ) boolean XOR operation. the computer could care less where the network bits begin and end. Chuck -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of archsteinSent: Monday, November 13, 2000 8:28 PMTo: [EMAIL PROTECTED]Subject: Summarization Hi groups... Can you help me please ? What is summary address for subnet 128.213.64.0 - 128.213.95.0 ? Is that right if the summary address is 128.213.64.0 255.255.192.0 To determine ther sumary route, the router looks for the most highest-order number of bits that match. If there is no match bits, how to summarize ??? Thanks
Re: Summarization (Doyle's book)
Daniel, My Doyle book is at home (I know, I should carry it with me at all times), but...I think the answer /23 is correct. If you consider your chart below, the first 7 bits (0001 000) are the same, not just the first 4. Add those 7 to the previous 16 bits from the first two octets and you get 23 bits in the mask. Remember that the summarization is based on the number of matching bits in the different addresses - those bits can be either 1s or 0s. 192.168.16.0/24.0001 192.168.17.0/24.0001 0001 ^^^ Matthew C. Sypherd CCNP+Security CCDP CCSE MCSE CCIE-R/S-Written "Daniel" <[EMAIL PROTECTED]>@groupstudy.com 11/05/2000 12:18 PM Please respond to "Daniel" <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] To: [EMAIL PROTECTED] cc: Subject: Summerization (Doyle's book) I search the archives, looked at the errata for Routing tcp/ip and did not find a correction for the following scenario. Chapt 8 P 373 figure 8.34 Wouldn't the summerization for 192.168.16.0/24.0001 192.168.17.0/24.0001 0001 be 192.168.16.0 /20? The example states 192.168.16.0/23 as the answer Why /23 ? Is this a typo or is there something I am missing? All the other summerization were right on. Thanks, Daniel _ 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: Summarization
Sorry for the html but I thought color would allow you to visualize. 22 would be the answer. A 0 is still a bit so they would be common. ( red is the same - black is not) if you used a /12 that would be a major aggregate and you would loose a lot of address space. a /22 would be a good answer for advertising out of an area a /12 would be better suited for an Autonomous system all this red is common all the black is different looks like a /22 to me. > 172.16.1.0 in bin -- 10110110.0001.0001.> 172.16.2.0 in bin-->10110110.0001.0010.> 172.16.3.0 in bin-->10110110.0001.0011. if you used a /12 you would lose all this address space (marked in green) that you could use elsewhere. all the red is common all the green and black combined is different but you could lengthen the mask to make better use of vlsm. > 172.16.1.0 in bin -- 10110110.0001.0001.> 172.16.2.0 in bin-->10110110.0001.0010.> 172.16.3.0 in bin-->10110110.0001.0011. So the real answer is they will both work but what do you want to advertise to and will you need the address space Duck - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Thursday, October 19, 2000 3:11 AM Subject: Re: Summarization > In a message dated 10/19/00 5:53:17 AM Eastern Daylight Time, > [EMAIL PROTECTED] writes:> > > > I feel the summarized supernet route should be 172.16.1.0/22> > > > from the below fig ..its clear that the no of common bits in the MSB part is> > 22> > > > It can't be 172.16.1.0/22 because the address of 172.16.2.0 does not share a > 1 bit with the rest. I thought it was supposed to be the leftmost common > "bit" for the mask. If so, wouldn't it then be 172.16.0.0/12. If you say it's > 22 then it's not the leftmost common bit, it's the leftmost > common...umm...space. ;) Can somebody give a positive answer? Thanks...> > 172.16.1.0 in bin -->10110110.0001.0001.> 172.16.2.0 in bin-->10110110.0001.0010.> 172.16.3.0 in bin-->10110110.0001.0011.> > > Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP> [EMAIL PROTECTED]">[EMAIL PROTECTED]> > "If you need luck, apparently you're not prepared...Go study!"> > ~Mark Zabludovsky~> > _> FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Summarization
yes, the correct answer here depends on ypur level of precision desired. It depends on whether or not you want the 172.16.0.0 to be included. Many routing protocols auto summarize, sometimes to the detriment of precision. I personally do not like to include routes in a summary that are not present, put this is due to my isp experience. Brian On Thu, 19 Oct 2000, Daniel Cotts wrote: > Implicit in the concept of summarization is that all possible subnets are > included in the sumarization. A summary of 172.16.0.0/22 would include four > subnets (172.16.0.0, 172.16.1.0, 172.16.2.0, 172.16.3.0). The first 22 bits > of all addresses are the same. Only the last two change. (00, 01, 10, 11). > 172.16.1.0/22 is not correct. BTW since summarization works on powers of two > the beginning address will always be an even number. > 172.16.0.0/22 works but does not include the first subnet. Geoff's answer > covers only the stated subnets. > > > -Original Message- > > From: Daniel Boutet [mailto:[EMAIL PROTECTED]] > > Sent: Thursday, October 19, 2000 10:32 AM > > To: [EMAIL PROTECTED] > > Subject: Re: Summarization > > > > > > Ok, I am joining in a little late since the answer to the question is > > complete. I was wondering Geoff why are you stating " but since the > > 172.16.0.0 is not included" What do you mean? You've lost me. > > The rest of your explanation is also not understood. > > I started learning about "summarization" and I need further > > explanation if > > you do not mind. > > Thanks > > > > Daniel > > > > ""A. Geoffrey Cauchi"" <[EMAIL PROTECTED]> wrote in message > > 014001c039b8$d7037e70$[EMAIL PROTECTED]">news:014001c039b8$d7037e70$[EMAIL PROTECTED]... > > > 172.16.1.0/22 is not correct. 172.16.0.0/22 would be the > > correct syntax, > > > but since the 172.16.0.0 is not included, I would aggregate these 3 > > networks > > > as: > > > > > > 172.16.1.0 > > > 172.16.2.0/23 > > > > > > > > > Geoff > > > > > > > > _ > 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: Summarization
Implicit in the concept of summarization is that all possible subnets are included in the sumarization. A summary of 172.16.0.0/22 would include four subnets (172.16.0.0, 172.16.1.0, 172.16.2.0, 172.16.3.0). The first 22 bits of all addresses are the same. Only the last two change. (00, 01, 10, 11). 172.16.1.0/22 is not correct. BTW since summarization works on powers of two the beginning address will always be an even number. 172.16.0.0/22 works but does not include the first subnet. Geoff's answer covers only the stated subnets. > -Original Message- > From: Daniel Boutet [mailto:[EMAIL PROTECTED]] > Sent: Thursday, October 19, 2000 10:32 AM > To: [EMAIL PROTECTED] > Subject: Re: Summarization > > > Ok, I am joining in a little late since the answer to the question is > complete. I was wondering Geoff why are you stating " but since the > 172.16.0.0 is not included" What do you mean? You've lost me. > The rest of your explanation is also not understood. > I started learning about "summarization" and I need further > explanation if > you do not mind. > Thanks > > Daniel > > ""A. Geoffrey Cauchi"" <[EMAIL PROTECTED]> wrote in message > 014001c039b8$d7037e70$[EMAIL PROTECTED]">news:014001c039b8$d7037e70$[EMAIL PROTECTED]... > > 172.16.1.0/22 is not correct. 172.16.0.0/22 would be the > correct syntax, > > but since the 172.16.0.0 is not included, I would aggregate these 3 > networks > > as: > > > > 172.16.1.0 > > 172.16.2.0/23 > > > > > > Geoff > > > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization
The key is to answer the question. A supernet route refers to a single route rather than the complete set of aggregate routes. While Geoff is correct and technically more accurate, the better answer belongs to Thangs who is also correct. >From: "A. Geoffrey Cauchi" <[EMAIL PROTECTED]> >Reply-To: "A. Geoffrey Cauchi" <[EMAIL PROTECTED]> >To: "thangs" <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>, ><[EMAIL PROTECTED]> >CC: <[EMAIL PROTECTED]> >Subject: Re: Summarization >Date: Thu, 19 Oct 2000 12:39:20 +0200 > >172.16.1.0/22 is not correct. 172.16.0.0/22 would be the correct syntax, >but since the 172.16.0.0 is not included, I would aggregate these 3 >networks >as: > >172.16.1.0 >172.16.2.0/23 > > >Geoff > >- Original Message - >From: "thangs" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> >Cc: <[EMAIL PROTECTED]> >Sent: Thursday, October 19, 2000 10:22 PM >Subject: Re: Summarization > > > > I feel the summarized supernet route should be 172.16.1.0/22 > > > > from the below fig ..its clear that the no of common bits in the MSB >part >is > > 22 > > > > | > > If you expand 172.16.1.0 in bin ->10110110.0001.00 >|01. > > 172.16.2.0 in bin-->10110110.0001.00 > > |10. > > 172.16.3.0 in bin-->10110110.00010000.00 > > |10. > > > > | > > > > Thanks > > Thangavel > > > > - Original Message - > > | > > From: <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Cc: <[EMAIL PROTECTED]> > > Sent: Thursday, October 19, 2000 3:57 AM > > Subject: Re: Summarization > > > > > > > In a message dated 10/19/00 4:33:48 AM Eastern Daylight Time, > > > [EMAIL PROTECTED] writes: > > > > > > > > > > Hi All, > > > > > > > > There are 3 contiguous networks: > > > > 172.16.1.0/24 > > > > 172.16.2.0/24 > > > > 172.16.3.0/24 > > > > What is the supernet ? > > > > Is it 172.16.1.0/22 ? Would you pls explain to me ? > > > > > > > > TIA, > > > > > > > > > > That is not the supernet because 172.16.2.0 does not have a common bit > > place > > > in 172.16.1.0/22. I believe that this would be superneted to > > 172.16.0.0/16. > > > This is where I see them all matching up that is. It would be real >hard > > for > > > me to explain this so I'll let someone else do that who is more > > experienced > > > with this. Hope I helped a little. > > > > > > Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP > > > [EMAIL PROTECTED] > > > > > > "If you need luck, apparently you're not prepared...Go study!" > > > > > >~Mark Zabludovsky~ > > > > > > _ > > > 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] > > > >_ >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: Summarization
Ok, I am joining in a little late since the answer to the question is complete. I was wondering Geoff why are you stating " but since the 172.16.0.0 is not included" What do you mean? You've lost me. The rest of your explanation is also not understood. I started learning about "summarization" and I need further explanation if you do not mind. Thanks Daniel ""A. Geoffrey Cauchi"" <[EMAIL PROTECTED]> wrote in message 014001c039b8$d7037e70$[EMAIL PROTECTED]">news:014001c039b8$d7037e70$[EMAIL PROTECTED]... > 172.16.1.0/22 is not correct. 172.16.0.0/22 would be the correct syntax, > but since the 172.16.0.0 is not included, I would aggregate these 3 networks > as: > > 172.16.1.0 > 172.16.2.0/23 > > > Geoff > > - Original Message - > From: "thangs" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]> > Sent: Thursday, October 19, 2000 10:22 PM > Subject: Re: Summarization > > > > I feel the summarized supernet route should be 172.16.1.0/22 > > > > from the below fig ..its clear that the no of common bits in the MSB part > is > > 22 > > > > | > > If you expand 172.16.1.0 in bin ->10110110.0001.00 > |01. > > 172.16.2.0 in bin-->10110110.0001.00 > > |10. > > 172.16.3.0 in bin-->10110110.0001.00 > > |10. > > > > | > > > > Thanks > > Thangavel > > > > - Original Message - > > | > > From: <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Cc: <[EMAIL PROTECTED]> > > Sent: Thursday, October 19, 2000 3:57 AM > > Subject: Re: Summarization > > > > > > > In a message dated 10/19/00 4:33:48 AM Eastern Daylight Time, > > > [EMAIL PROTECTED] writes: > > > > > > > > > > Hi All, > > > > > > > > There are 3 contiguous networks: > > > > 172.16.1.0/24 > > > > 172.16.2.0/24 > > > > 172.16.3.0/24 > > > > What is the supernet ? > > > > Is it 172.16.1.0/22 ? Would you pls explain to me ? > > > > > > > > TIA, > > > > > > > > > > That is not the supernet because 172.16.2.0 does not have a common bit > > place > > > in 172.16.1.0/22. I believe that this would be superneted to > > 172.16.0.0/16. > > > This is where I see them all matching up that is. It would be real hard > > for > > > me to explain this so I'll let someone else do that who is more > > experienced > > > with this. Hope I helped a little. > > > > > > Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP > > > [EMAIL PROTECTED] > > > > > > "If you need luck, apparently you're not prepared...Go study!" > > > > > >~Mark Zabludovsky~ > > > > > > _ > > > 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] > > > > _ > 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: Summarization
I beleive Geoff is right. Thanks Thangavel - Original Message - From: A. Geoffrey Cauchi <[EMAIL PROTECTED]> To: thangs <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Thursday, October 19, 2000 5:39 AM Subject: Re: Summarization > 172.16.1.0/22 is not correct. 172.16.0.0/22 would be the correct syntax, > but since the 172.16.0.0 is not included, I would aggregate these 3 networks > as: > > 172.16.1.0 > 172.16.2.0/23 > > > Geoff > > - Original Message - > From: "thangs" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]> > Sent: Thursday, October 19, 2000 10:22 PM > Subject: Re: Summarization > > > > I feel the summarized supernet route should be 172.16.1.0/22 > > > > from the below fig ..its clear that the no of common bits in the MSB part > is > > 22 > > > > | > > If you expand 172.16.1.0 in bin ->10110110.0001.00 > |01. > > 172.16.2.0 in bin-->10110110.0001.00 > > |10. > > 172.16.3.0 in bin-->10110110.0001.00 > > |10. > > > > | > > > > Thanks > > Thangavel > > > > - Original Message - > > | > > From: <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Cc: <[EMAIL PROTECTED]> > > Sent: Thursday, October 19, 2000 3:57 AM > > Subject: Re: Summarization > > > > > > > In a message dated 10/19/00 4:33:48 AM Eastern Daylight Time, > > > [EMAIL PROTECTED] writes: > > > > > > > > > > Hi All, > > > > > > > > There are 3 contiguous networks: > > > > 172.16.1.0/24 > > > > 172.16.2.0/24 > > > > 172.16.3.0/24 > > > > What is the supernet ? > > > > Is it 172.16.1.0/22 ? Would you pls explain to me ? > > > > > > > > TIA, > > > > > > > > > > That is not the supernet because 172.16.2.0 does not have a common bit > > place > > > in 172.16.1.0/22. I believe that this would be superneted to > > 172.16.0.0/16. > > > This is where I see them all matching up that is. It would be real hard > > for > > > me to explain this so I'll let someone else do that who is more > > experienced > > > with this. Hope I helped a little. > > > > > > Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP > > > [EMAIL PROTECTED] > > > > > > "If you need luck, apparently you're not prepared...Go study!" > > > > > >~Mark Zabludovsky~ > > > > > > _ > > > 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] > > > > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization
172.16.1.0/22 is not correct. 172.16.0.0/22 would be the correct syntax, but since the 172.16.0.0 is not included, I would aggregate these 3 networks as: 172.16.1.0 172.16.2.0/23 Geoff - Original Message - From: "thangs" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Thursday, October 19, 2000 10:22 PM Subject: Re: Summarization > I feel the summarized supernet route should be 172.16.1.0/22 > > from the below fig ..its clear that the no of common bits in the MSB part is > 22 > > | > If you expand 172.16.1.0 in bin ->10110110.0001.00 |01. > 172.16.2.0 in bin-->10110110.0001.00 > |10. > 172.16.3.0 in bin-->10110110.0001.00 > |10. > > | > > Thanks > Thangavel > > - Original Message - > | > From: <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]> > Sent: Thursday, October 19, 2000 3:57 AM > Subject: Re: Summarization > > > > In a message dated 10/19/00 4:33:48 AM Eastern Daylight Time, > > [EMAIL PROTECTED] writes: > > > > > > > Hi All, > > > > > > There are 3 contiguous networks: > > > 172.16.1.0/24 > > > 172.16.2.0/24 > > > 172.16.3.0/24 > > > What is the supernet ? > > > Is it 172.16.1.0/22 ? Would you pls explain to me ? > > > > > > TIA, > > > > > > > That is not the supernet because 172.16.2.0 does not have a common bit > place > > in 172.16.1.0/22. I believe that this would be superneted to > 172.16.0.0/16. > > This is where I see them all matching up that is. It would be real hard > for > > me to explain this so I'll let someone else do that who is more > experienced > > with this. Hope I helped a little. > > > > Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP > > [EMAIL PROTECTED] > > > > "If you need luck, apparently you're not prepared...Go study!" > > > >~Mark Zabludovsky~ > > > > _ > > 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] > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization
- Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Thursday, October 19, 2000 5:11 AM Subject: Re: Summarization > In a message dated 10/19/00 5:53:17 AM Eastern Daylight Time, > [EMAIL PROTECTED] writes: > > > > I feel the summarized supernet route should be 172.16.1.0/22 > > > > from the below fig ..its clear that the no of common bits in the MSB part is 22 172.16.1.0 in bin -->10110110.0001.0001. > 172.16.2.0 in bin-->10110110.0001.0010. > 172.16.3.0 in bin-->10110110.0001.0011. > > > It can't be 172.16.1.0/22 because the address of 172.16.2.0 does not share a > 1 bit with the rest. I thought it was supposed to be the leftmost common > "bit" for the mask. If so, wouldn't it then be 172.16.0.0/12. If you say it's > 22 then it's not the leftmost common bit, it's the leftmost > common...umm...space. ;) Can somebody give a positive answer? Thanks... > > > > Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP > [EMAIL PROTECTED] > > "If you need luck, apparently you're not prepared...Go study!" > >~Mark Zabludovsky~ > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization
In a message dated 10/19/00 5:53:17 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > I feel the summarized supernet route should be 172.16.1.0/22 > > from the below fig ..its clear that the no of common bits in the MSB part is > 22 > It can't be 172.16.1.0/22 because the address of 172.16.2.0 does not share a 1 bit with the rest. I thought it was supposed to be the leftmost common "bit" for the mask. If so, wouldn't it then be 172.16.0.0/12. If you say it's 22 then it's not the leftmost common bit, it's the leftmost common...umm...space. ;) Can somebody give a positive answer? Thanks... 172.16.1.0 in bin -->10110110.0001.0001. 172.16.2.0 in bin-->10110110.0001.0010. 172.16.3.0 in bin-->10110110.0001.0011. Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP [EMAIL PROTECTED] "If you need luck, apparently you're not prepared...Go study!" ~Mark Zabludovsky~ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Summarization
Thanks for the answer, btw I have the answer is 172.16.1.0/22 from Lammle's CCNP ACRC Study Guide, is there any one have tried it on lab ? TIA Janto -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Thursday, October 19, 2000 3:58 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: Summarization In a message dated 10/19/00 4:33:48 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > Hi All, > > There are 3 contiguous networks: > 172.16.1.0/24 > 172.16.2.0/24 > 172.16.3.0/24 > What is the supernet ? > Is it 172.16.1.0/22 ? Would you pls explain to me ? > > TIA, > That is not the supernet because 172.16.2.0 does not have a common bit place in 172.16.1.0/22. I believe that this would be superneted to 172.16.0.0/16. This is where I see them all matching up that is. It would be real hard for me to explain this so I'll let someone else do that who is more experienced with this. Hope I helped a little. Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP [EMAIL PROTECTED] "If you need luck, apparently you're not prepared...Go study!" ~Mark Zabludovsky~ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization
I feel the summarized supernet route should be 172.16.1.0/22 from the below fig ..its clear that the no of common bits in the MSB part is 22 | If you expand 172.16.1.0 in bin ->10110110.0001.00 |01. 172.16.2.0 in bin-->10110110.0001.00 |10. 172.16.3.0 in bin-->10110110.0001.00 |10. | Thanks Thangavel - Original Message - | From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Thursday, October 19, 2000 3:57 AM Subject: Re: Summarization > In a message dated 10/19/00 4:33:48 AM Eastern Daylight Time, > [EMAIL PROTECTED] writes: > > > > Hi All, > > > > There are 3 contiguous networks: > > 172.16.1.0/24 > > 172.16.2.0/24 > > 172.16.3.0/24 > > What is the supernet ? > > Is it 172.16.1.0/22 ? Would you pls explain to me ? > > > > TIA, > > > > That is not the supernet because 172.16.2.0 does not have a common bit place > in 172.16.1.0/22. I believe that this would be superneted to 172.16.0.0/16. > This is where I see them all matching up that is. It would be real hard for > me to explain this so I'll let someone else do that who is more experienced > with this. Hope I helped a little. > > Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP > [EMAIL PROTECTED] > > "If you need luck, apparently you're not prepared...Go study!" > >~Mark Zabludovsky~ > > _ > 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: Summarization
In a message dated 10/19/00 4:33:48 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > Hi All, > > There are 3 contiguous networks: > 172.16.1.0/24 > 172.16.2.0/24 > 172.16.3.0/24 > What is the supernet ? > Is it 172.16.1.0/22 ? Would you pls explain to me ? > > TIA, > That is not the supernet because 172.16.2.0 does not have a common bit place in 172.16.1.0/22. I believe that this would be superneted to 172.16.0.0/16. This is where I see them all matching up that is. It would be real hard for me to explain this so I'll let someone else do that who is more experienced with this. Hope I helped a little. Mark Zabludovsky ~ CCNA, CCDA, 1/4-NP [EMAIL PROTECTED] "If you need luck, apparently you're not prepared...Go study!" ~Mark Zabludovsky~ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Summarization
try this http://www.cisco.com/univercd/cc/td/doc/cisintwk/idg4/nd2003.htm http://www.cisco.com/warp/public/103/eigrp5.html http://www.cisco.com/cpress/cc/td/cpress/design/ospf/on0407.htm http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/ip_c /ipcprt2/1cdrip.htm Oz http://www.mcseco-op.com/helpfull_links.htm ___ 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: Summarization
I recommend this web site that was advertised on the list recently (Hitesh Pathak) as an outstanding document to read on all things IP. Even route aggregation/summarisation. HYPERLINK http://www.3com.com/nsc/501302.html http://www.3com.com/nsc/501302.html Dan Mansfield MCSE, CNE, CLP soon to be CCNA! -Original Message- From: Brian Windle Sent: 31 August 2000 13:22 To: [EMAIL PROTECTED] Subject:Summarization I need to find resources about how to calculate summarized routes. Searching the archives on summarization, CIDR, etc. has not turned up anything. Thanks in advance Brian _ 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. ___ 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] > The information in this e-mail is confidential to the ordinary user of the e-mail address to which it was addressed. If you receive it in error, you should not use or disseminate the information in it; instead, please e-mail it back to the sender then delete the message from your system. Internet communications are not 100% secure and it is the responsibility of the recipient to ensure that this email has not been tampered with and that its attachments are virus free. > ___ 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]
