RE: Weekend Challenge - Route Aggregation
OK. No one else has nibbled. And as everyone knows, I'm not afraid to make a fool of myself publicly. So here goes.. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Howard C. Berkowitz Sent: Friday, December 15, 2000 9:18 PM To: [EMAIL PROTECTED] Subject: Re: Weekend Challenge - Route Aggregation >>SNIP for brevity<< And a counterchallenge -- anyone want to take a stab and suggest why certain of these might be being advertised as less-than-optimal aggregations, for quite good reasons? CL: as tempted as I am to crack wise about sloth and clue, it is more likely that the lack of aggregation has to do with downstream requirements and agreements in place. Far too many people are "load balancing on the internet". Whether they need to or not is a different issue. Note -- I have not researched whether these are or are not good aggregations. But where might I look? What is the single most important additional piece of information about each of these groups? CL: RADB database? www.radb.net ? ARIN WHOIS? www.arin.net ? CL: In terms of the internet backbone providers and Tier 1 ISP's, I suppose it becomes a matter of the amount of work involved, particularly after the spate of mergers in the last year or so. UUNet / MCI seems to be one of the major "offenders" in the lack of CIDR conformance. Having dealt with both in a limited fashion, I was highly impressed with their engineering prowess. Which leads me to believe that massive aggregation on their part would be no simple matter. CL: is this what you were getting at? > _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Weekend Challenge - Route Aggregation
>OK. No one else has nibbled. And as everyone knows, I'm not afraid to make a >fool of myself publicly. > >So here goes.. > >-Original Message- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of >Howard C. Berkowitz >Sent: Friday, December 15, 2000 9:18 PM >To: [EMAIL PROTECTED] >Subject: Re: Weekend Challenge - Route Aggregation > >>>SNIP for brevity<< > >And a counterchallenge -- anyone want to take a stab and suggest why >certain of these might be being advertised as less-than-optimal >aggregations, for quite good reasons? > >CL: as tempted as I am to crack wise about sloth and clue, it is more likely >that the lack of aggregation has to do with downstream requirements and >agreements in place. Far too many people are "load balancing on the >internet". Whether they need to or not is a different issue. I did have the opportunity to visit the National Zoo yesterday, and did refresh my knowledge on sloth(s). Load balancing is often only marginally achievable, at best. Fault tolerance is another matter. Consider the following scenario, which is basic but very real world. AS1 is an B2C service provider with critical application requirements. It obtains an AS number, but not its own address space (which is a perfectly legal scenario). AS1 has two upstreams, AS2 and AS3. AS1 receives a delegation of provider-assigned address space from AS2. AS2's block, hypothetically, is 96.0.0.0/14. It delegates 96.0.0.0/22 to AS1. AS1, AS2, and AS3 reach administrative agreement that AS3 will advertise that part of AS2's space that is delegated to AS1, so the Internet can see paths to AS1's 96.0.0.0/22 via AS2 and AS3. One of the things that breaks aggregation, however, is that if AS2 only advertises its best aggregate, 96.0.0.0/14, _no_ traffic outside AS2 destined for 96.0.0.0/22 will enter AS2. Instead, since AS3 is offering the more specific route to 96.0.0.0/22, all incoming traffic to AS1 will come through AS3, even though it is going to AS2 address space. In order to send a plausible route to the rest of the Internet, AS2 must advertise both the aggregate 96.0.0.0/14 and the more-specific 96.0.0.0/22. AS3 must also advertise 96.0.0.0/22. So, AS2, for legitimate reasons, is sending less-than-optimally-aggregated announcements. > >Note -- I have not researched whether these are or are not good >aggregations. But where might I look? What is the single most >important additional piece of information about each of these groups? Even more basic, although you'll use it to use the resources you listed. I was thinking of the originating AS number. > >CL: RADB database? www.radb.net ? ARIN WHOIS? www.arin.net ? > >CL: In terms of the internet backbone providers and Tier 1 ISP's, I suppose >it becomes a matter of the amount of work involved, particularly after the >spate of mergers in the last year or so. UUNet / MCI seems to be one of the >major "offenders" in the lack of CIDR conformance. Having dealt with both in >a limited fashion, I was highly impressed with their engineering prowess. >Which leads me to believe that massive aggregation on their part would be no >simple matter. For the legitimate technical reasons listed below, as well as less legitimate ones (commercial or just plain cluelessness). In addition, very large providers such as you name may or may not have different AS numbers on a continental or other large regional basis, and may send what seem to be less than optimal aggregates simply to reach another part of their own service. _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Weekend Challenge - Route Aggregation
> In order to send a plausible route to the rest of the Internet, AS2 > must advertise both the aggregate 96.0.0.0/14 and the more-specific > 96.0.0.0/22. AS3 must also advertise 96.0.0.0/22. So, AS2, for > legitimate reasons, is sending less-than-optimally-aggregated > announcements. This of course is the obvious answer to the question. Another part would be that AS1 should be able to advertise that space any way it would like to, like with prepends for instance. If AS2 aggregated anyway, not only would they not recieve any traffic, but they would create an atomic aggregate that looses the intended information announced by AS1. When this was first written I didn't respond though because I actually checked some route servers (for the first set of addresses anyway) and the ASPATH indicated they were not multihomed and that the provider owned the entire class B. So I really couldn't think of a good reason to announce more specific space without multihoming. andy _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Weekend Challenge - Route Aggregation
GRP1 143.178.0.0 /19 GRP2 148.233.0.0 /24 GRP3 148.235.0.0 /17 GRP4 148.233.110.0 /19 don`t know if ti`s right but ATLEAST it`s an answer steve >From: "Chuck Larrieu" <[EMAIL PROTECTED]> >Reply-To: "Chuck Larrieu" <[EMAIL PROTECTED]> >To: "Cisco Mail List" <[EMAIL PROTECTED]> >Subject: Weekend Challenge - Route Aggregation >Date: Fri, 15 Dec 2000 19:18:30 -0800 > >Just sitting around eating some chicken, catching up on my e-mail. I see in >the Tony Bates CIDR report to the NANOG list there is a reference to >"interesting aggregations". > >http://www.employees.org/~tbates/cidr-report.html#Aggs > >Thought some excerpts might make an interesting challenge. To whit, come up >with the appropriate summarization for the following routes that currently >appear in the "global internet BGP table" > >These are things that caught my eye while browsing the report. I have not >tried to summarize them myself as yet. > >How about it? Take a stab and publish your results? Have some fun? > >Group 1 >143.178.0.0/19 >143.178.64.0/19 >143.178.128.0/19 >143.178.140.0/24 > >Group 2 >148.233.0.0/21 >148.233.1.0/24 >148.233.2.0/24 >148.233.6.0/24 >148.233.8.0/21 > >Group 3 >148.235.0.0/17 >148.235.2.0/24 >148.235.4.0/23 >148.235.6.0/24 >148.235.8.0/21 > >Group 4 - the Big Challenge >148.223.112.0/21 >148.223.120.0/22 >148.223.124.0/24 >148.223.128.0/17 >148.223.128.0/20 >148.223.151.0/24 >148.223.160.0/24 >148.223.176.0/20 >148.223.177.0/24 >148.223.178.0/24 >148.223.192.0/19 >148.223.224.0/23 >148.223.226.0/24 >148.223.249.0/24 >148.223.250.0/24 >148.233.110.0/24 >148.233.112.0/20 >148.233.113.0/24 >148.233.116.0/22 >148.233.120.0/21 >148.233.122.0/24 >148.233.128.0/21 >148.233.128.0/24 >148.233.130.0/24 >148.233.137.0/24 >148.233.140.0/22 >148.233.140.0/24 >148.233.155.0/24 >148.233.156.0/22 >148.233.160.0/20 >148.233.160.0/21 >148.233.164.0/24 >148.233.165.0/24 >148.233.168.0/22 >148.233.175.0/24 >148.233.176.0/20 > >One way to determine how well we understand aggregation / supernetting / >CIDR :-> > >Chuck >-- >I am Locutus, a CCIE Lab Proctor. Xx_Brain_dumps_xX are futile. Your life >as >it has been is over ( if you hope to pass ) From this time forward, you >will >study US! >( apologies to the folks at Star Trek TNG ) > >_ >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. _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Weekend Challenge - Route Aggregation
My ans are GRP1: 143.178.0.0/16- only first 16 bits are common GRP2: 148.233.0.0/20 GRP3: 148.135.0.0/17 GRP4: 148.233.96.0/20 148.233.128.0/17 Duno right or wrong ? Rgds, Sam > -Original Message- > From: Stephen Skinner [SMTP:[EMAIL PROTECTED]] > Sent: Tuesday, December 19, 2000 4:17 AM > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: Re: Weekend Challenge - Route Aggregation > > GRP1 143.178.0.0 /19 > GRP2 148.233.0.0 /24 > GRP3 148.235.0.0 /17 > GRP4 148.233.110.0 /19 > > don`t know if ti`s right but ATLEAST it`s an answer > > steve > > > > >From: "Chuck Larrieu" <[EMAIL PROTECTED]> > >Reply-To: "Chuck Larrieu" <[EMAIL PROTECTED]> > >To: "Cisco Mail List" <[EMAIL PROTECTED]> > >Subject: Weekend Challenge - Route Aggregation > >Date: Fri, 15 Dec 2000 19:18:30 -0800 > > > >Just sitting around eating some chicken, catching up on my e-mail. I see > in > >the Tony Bates CIDR report to the NANOG list there is a reference to > >"interesting aggregations". > > > >http://www.employees.org/~tbates/cidr-report.html#Aggs > > > >Thought some excerpts might make an interesting challenge. To whit, come > up > >with the appropriate summarization for the following routes that > currently > >appear in the "global internet BGP table" > > > >These are things that caught my eye while browsing the report. I have not > >tried to summarize them myself as yet. > > > >How about it? Take a stab and publish your results? Have some fun? > > > >Group 1 > >143.178.0.0/19 > >143.178.64.0/19 > >143.178.128.0/19 > >143.178.140.0/24 > > > >Group 2 > >148.233.0.0/21 > >148.233.1.0/24 > >148.233.2.0/24 > >148.233.6.0/24 > >148.233.8.0/21 > > > >Group 3 > >148.235.0.0/17 > >148.235.2.0/24 > >148.235.4.0/23 > >148.235.6.0/24 > >148.235.8.0/21 > > > >Group 4 - the Big Challenge > >148.223.112.0/21 > >148.223.120.0/22 > >148.223.124.0/24 > >148.223.128.0/17 > >148.223.128.0/20 > >148.223.151.0/24 > >148.223.160.0/24 > >148.223.176.0/20 > >148.223.177.0/24 > >148.223.178.0/24 > >148.223.192.0/19 > >148.223.224.0/23 > >148.223.226.0/24 > >148.223.249.0/24 > >148.223.250.0/24 > >148.233.110.0/24 > >148.233.112.0/20 > >148.233.113.0/24 > >148.233.116.0/22 > >148.233.120.0/21 > >148.233.122.0/24 > >148.233.128.0/21 > >148.233.128.0/24 > >148.233.130.0/24 > >148.233.137.0/24 > >148.233.140.0/22 > >148.233.140.0/24 > >148.233.155.0/24 > >148.233.156.0/22 > >148.233.160.0/20 > >148.233.160.0/21 > >148.233.164.0/24 > >148.233.165.0/24 > >148.233.168.0/22 > >148.233.175.0/24 > >148.233.176.0/20 > > > >One way to determine how well we understand aggregation / supernetting / > >CIDR :-> > > > >Chuck > >-- > >I am Locutus, a CCIE Lab Proctor. Xx_Brain_dumps_xX are futile. Your life > > >as > >it has been is over ( if you hope to pass ) From this time forward, you > >will > >study US! > >( apologies to the folks at Star Trek TNG ) > > > >_ > >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. > > _ > 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: Weekend Challenge - Route Aggregation
>Just sitting around eating some chicken, catching up on my e-mail. I see in >the Tony Bates CIDR report to the NANOG list there is a reference to >"interesting aggregations". > >http://www.employees.org/~tbates/cidr-report.html#Aggs > >Thought some excerpts might make an interesting challenge. To whit, come up >with the appropriate summarization for the following routes that currently >appear in the "global internet BGP table" > >These are things that caught my eye while browsing the report. I have not >tried to summarize them myself as yet. > >How about it? Take a stab and publish your results? Have some fun? And a counterchallenge -- anyone want to take a stab and suggest why certain of these might be being advertised as less-than-optimal aggregations, for quite good reasons? Note -- I have not researched whether these are or are not good aggregations. But where might I look? What is the single most important additional piece of information about each of these groups? > >Group 1 >143.178.0.0/19 >143.178.64.0/19 >143.178.128.0/19 >143.178.140.0/24 > >Group 2 >148.233.0.0/21 >148.233.1.0/24 >148.233.2.0/24 >148.233.6.0/24 >148.233.8.0/21 > >Group 3 >148.235.0.0/17 >148.235.2.0/24 >148.235.4.0/23 >148.235.6.0/24 >148.235.8.0/21 > >Group 4 - the Big Challenge >148.223.112.0/21 >148.223.120.0/22 >148.223.124.0/24 >148.223.128.0/17 >148.223.128.0/20 >148.223.151.0/24 >148.223.160.0/24 >148.223.176.0/20 >148.223.177.0/24 >148.223.178.0/24 >148.223.192.0/19 >148.223.224.0/23 >148.223.226.0/24 >148.223.249.0/24 >148.223.250.0/24 >148.233.110.0/24 >148.233.112.0/20 >148.233.113.0/24 >148.233.116.0/22 >148.233.120.0/21 >148.233.122.0/24 >148.233.128.0/21 >148.233.128.0/24 >148.233.130.0/24 >148.233.137.0/24 >148.233.140.0/22 >148.233.140.0/24 >148.233.155.0/24 >148.233.156.0/22 >148.233.160.0/20 >148.233.160.0/21 >148.233.164.0/24 >148.233.165.0/24 >148.233.168.0/22 >148.233.175.0/24 >148.233.176.0/20 > >One way to determine how well we understand aggregation / supernetting / >CIDR :-> > >Chuck >-- >I am Locutus, a CCIE Lab Proctor. Xx_Brain_dumps_xX are futile. Your life as >it has been is over ( if you hope to pass ) From this time forward, you will >study US! >( apologies to the folks at Star Trek TNG ) > >_ >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]
