May 1999 - Test - lists.nanog.org

The Cidr Report
by Tony Bates 28 May '99

28 May '99

This is an auto-generated mail on Fri May 28 12:00:02 PDT 1999 It is not checked before it leaves my workstation. However, hopefully you will find this report interesting and will take the time to look through this to see if you can improve the amount of aggregation you perform. The report is split into sections: 0) General Status List the route table history for the last week, list any possibly bogus routes seen and give some status on ASes. 1) Gains by aggregating at the origin AS level This lists the "Top 30" players who if they decided to aggregate their announced classful prefixes at the origin AS level could make a significant difference in the reduction of the current size of the Internet routing table. This calculation does not take into account the inclusion of holes when forming an aggregate so it is possible even larger reduction should be possible. 2) Weekly Delta A summary of the last weeks changes in terms of withdrawn and added routes. Please note that this is only a snapshot but does give some indication of ASes participating in CIDR. Clearly, it is generally a good thing to see a large amont of withdrawls. 3) Interesting aggregates Interesting here means not an aggregate made as a set of classful routes. Thanks to xara.net for giving me access to their routing tables once a day. Please send any comments about this report directly to me. Check http://www.employees.org/~tbates/cidr-report.html for a daily update of this report. ------------------------------------------------------------------------------ CIDR REPORT for 28May99 0) General Status Table History ------------- Date Prefixes 210599 59570 220599 59339 230599 59259 240599 59294 250599 59763 260599 60611 270599 60580 280599 60794 Check http://www.employees.org/~tbates/cidr.plot.html for a plot of the table history. Possible Bogus Routes --------------------- *** Bogus 221.43.160.0/19 from AS12323 AS Summary ---------- Number of ASes in routing system: 5031 Number of ASes announcing only one prefix: 2576 (1405 cidr, 1171 classful) Largest number of cidr routes: 406 announced by AS701 Largest number of classful routes: 1226 announced by AS209 1) Gains by aggregating at the origin AS level --- 28May99 --- ASnum NetsNow NetsCIDR NetGain % Gain Description AS209 1226 567 659 53.8% Qwest Communications AS271 358 147 211 58.9% BCnet Backbone AS4293 273 168 105 38.5% IMCI AS174 582 488 94 16.2% Performance Systems International AS4755 172 86 86 50.0% Videsh Sanchar Nigam Ltd. India AS577 255 176 79 31.0% Bell Canada Backbone AS4200 169 93 76 45.0% AGIS (Apex Global Information Ser AS3749 136 62 74 54.4% TECNET AS1267 94 24 70 74.5% IUNET-AS AS7496 99 33 66 66.7% Power Up AS7545 112 48 64 57.1% TPG Internet Pty Ltd AS7122 139 78 61 43.9% MTS ADVANCED Network Policy AS1221 457 396 61 13.3% TELSTRA-AS AS7657 179 122 57 31.8% The Internet Group Limited AS10928 111 54 57 51.4% UNKNOWN AS9269 65 10 55 84.6% Hong Kong CTI AS72 94 39 55 58.5% Schlumberger Information Network AS4740 325 270 55 16.9% Ozemail Pty Ltd (ASN-OZEMAIL) AS719 474 420 54 11.4% LANLINK autonomous system AS1239 526 472 54 10.3% SprintLink Backbone AS2493 175 122 53 30.3% iSTAR Internet, Inc. AS7046 265 213 52 19.6% UUNET-CUSTOMER AS3737 161 111 50 31.1% PenTeleData Inc. (ASN-PTD) AS803 73 37 36 49.3% SaskNet Backbone AS1 495 460 35 7.1% BBNPLANET AS6172 153 120 33 21.6% HOME-NET-1 AS1785 246 214 32 13.0% NYSERNet Backbone AS549 163 132 31 19.0% ONet Backbone AS4307 32 1 31 96.9% SVINET-1 AS3549 133 102 31 23.3% Frontier GlobalCenter For the rest of the previous weeks gain information please see http://www.employees.org:80/~tbates/cidr-report.html 2) Weekly Delta Please see http://www.employees.org:80/~tbates/cidr-report.html for this part of the report 3) Interesting aggregates Please see http://www.employees.org:80/~tbates/cidr-report.html for this part of the report

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One Big Box Design
by Sean Donelan 28 May '99

28 May '99

Of course with the "one big box" design, even if you design it to so-called "telco-quality" standards you still have the problem of loosing a lot when the "big box" goes down. Someone pointed out to me that last night seven Missouri counties lost 9-1-1 service and long-distance service for over four hours (and a plane crashed, but that was unrelated). Southwestern Bell reports an 'unknown party' cut a fiber optic cable in Lake St. Louis (just west of St. Louis) around 2pm CDT yesterday. Cell phones, pagers, 800 numbers were out of service from about Jefferson City to Lake St. Louis. If you had a direct T1 to an IXC you could call long-distance, but Equal Access dialing was down. The 'unknown party' just happened to sever the fiber optic link for the main access tandem for the central(westphalia) LATA in Missouri. When you lose an access tandem in the telephone network, things don't work so good. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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Recommended NON-VIP based 7500 swtching paths
by Brandon Applegate 28 May '99

28 May '99

Greetings, I was looking to get some feedback as to what people are using in production on 75XX routers on standard line cards (HIP for example) for switching paths. I read one time on Cisco's site that on a 7500 non-vip router, you can see up to 150k PPS using plain fast-switching, and up to 275k by using optimum. Could someone be kind enough to elaborate on the differences between fast/optimum switching other than the addition of 'optimum' on the command line ?? I dont remeber seeing too much detailed info on the differences of these earlier switching paths on CCO. Feel free to reply directly via email/off-list. Thanks in advance. -------------------------------------------------- Brandon Applegate, CCNA : Network Administrator http://www.one.net : brandon(a)one.net --------------------------------------------------

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Re: OSPF multi-level hierarchy: Necessary at all?
by Alex Zinin 28 May '99

28 May '99

At 15:11 28.05.99 +0400, Alex P. Rudnev wrote: >Btw. Flat network... > >Routers now have - 128 or 256 MB RAM, 300 - 400 Mhz CPU. I guess you can >built flat betwork with 5,000 routers withouth hard problems. Mmm...I wouldn't be so sure, actually. Recall we need to refresh each LSA every 30 minutes not to let some bugs drive our network crazy. Also the more routers you have in the flat network the greater is the size of LSDB (or whatever table is used) and, since all routers see all other routers and links, the more CPU time we need to spent calculating our SPFs, maintaining the RT, etc... > >Through it's not the question. There is _already_ 2 levels; you can use >multi-zone OSPF (independent OSPF networks connected by _redistribute_). >The question was _is 2-level hierarchy enougph__? Externals in OSPF can also become a scalability issue---Type5 LSAs have domain-wide flooding scope....so, unless you want your areas to be stub, you have all your externals crossing all areas and installed into LSDBs of all routers, making them spend more time on SPF, while it is understood that the lower the level of hierarchy a router is in, the less granularity of external routing info it needs. Alex. ------------------------------------------------------------------ Alex D. Zinin, Consultant CCSI #98966 CCIE #4015 AMT Group / ISL Cisco Systems Gold Certified Partner http://www.amt.ru irc: //EFNET/#cisco, //irc.msn.com/#NetCisco [Ustas]

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Re: OSPF multi-level hierarchy: Necessary at all?
by Alex Zinin 28 May '99

28 May '99

At 15:33 27.05.99 -0700, Vadim Antonov wrote: >Tony Li <tony1(a)home.net> wrote: > >>I suspect that the main driver is not the amount of routing information >>in the gross sense, but the scalability of the protocol as the number of >>nodes increases. > >There's a better solution: decrease the number of nodes by replacing >clusters with bigger boxes. This has an additional advantage of reducing >number of hops (and, consequently, latency variance). "Have more bigger boxes rather than less smaller ones"-approach is not for everybody and not for every case. If you have clusters sitting in one room, powered from the same source, sharing the same ceiling that can fall, running the same version of soft, using the same config., etc., than yes it's ok, because they will more likely crash at the same moment. Otherwise, I'd think first. Also, even if you do use a large box, you probably don't wanna know all the details about it's connections at some level of your network. > >PS. Using DUAL or DASM instead of SPF helps, too -- these algorithms tend > to eliminate updates which "do not matter" unlike SPF-based algorithms > which have to inform everyone about local topology changes. In SPF-based protocols we have areas for this purpose---we do not propogate topology information across the area boundaries. Also, magically we don't have SIAs in SPF even when there's a lot of traffic :) ------------------------------------------------------------------ Alex D. Zinin, Consultant CCSI #98966 CCIE #4015 AMT Group / ISL Cisco Systems Gold Certified Partner http://www.amt.ru irc: //EFNET/#cisco, //irc.msn.com/#NetCisco [Ustas]

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Re: OSPF multi-level hierarchy: Necessary at all?
by Sean Donelan 28 May '99

28 May '99

avg(a)kotovnik.COM (Vadim Antonov) writes: >Well, actually it is not that bad. The biggest number of locations is >probably found in AT&T phone network - 250 or so. Sprint is in few >dozen. The existing IGPs are quite happy with that kind of complexity, >so if you belong to the "one-router-per-POP" school of thought the >IGP complexity is a non-issue. Well, the phone system is already hierarchial. The top-level is pretty small, it is the second and third levels which are monsters. There are about 100,000 NXX's in the country. California has the largest state with about 12,000. The Los Angeles LATA is the biggest at about 5,000. Within PacBell there are about 800 CLLI locations for the Los Angeles LATA, not including all the other CLECs who may have locations in LA. Getting from the relatively few IXC access tandems to those 800 locations is the trick. I may be doing something wrong, but I've found OSPF gets a bit cranky with far less than 800 routers and 5,000 routes in an area. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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RE: OSPF multi-level hierarch: side question
by Dan Rabb 28 May '99

28 May '99

Routers will inevitably fail. The question becomes how much exposure do you want when it does? Placing large amounts of customers on a single box is more economical, and is long as you have an uplink to your network with enough bandwidth to support them it's not a problem, but how many customers do you want down when a single router fails? This is obviously more of a political question that an operational one. Dan Rabb > -----Original Message----- > From: Steve Meuse [mailto:smeuse@bbnplanet.com] > Sent: 28 May, 1999 1:59 AM > To: Vadim Antonov > Cc: nanog(a)merit.edu > Subject: Re: OSPF multi-level hierarch: side question > > > > At 03:33 PM 05/27/1999 -0700, Vadim Antonov wrote: > > > >Tony Li <tony1(a)home.net> wrote: > > > >>I suspect that the main driver is not the amount of routing > information > >>in the gross sense, but the scalability of the protocol as > the number of > >>nodes increases. > > > >There's a better solution: decrease the number of nodes by replacing > >clusters with bigger boxes. This has an additional > advantage of reducing > >number of hops (and, consequently, latency variance). > > > >K.I.S.S. rulez :) > > > >--vadim > > Side question: > > At what point do we stop aggregating customers onto a single box? The > technology exists now to have hundreds if not thousands of > customers on a > signle box, but, Do we want that many? > > -Steve > > >

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Re: OSPF multi-level hierarchy: Necessary at all?
by Vadim Antonov 27 May '99

27 May '99

Tony Li <tony1(a)home.net> wrote: >> There's a better solution: decrease the number of nodes by replacing >> clusters with bigger boxes. This has an additional advantage of reducing >> number of hops (and, consequently, latency variance). >Certainly that helps, but as we move forward you still end up with lots of >boxes in the network simply because you're in many different geographic >locations. Well, actually it is not that bad. The biggest number of locations is probably found in AT&T phone network - 250 or so. Sprint is in few dozen. The existing IGPs are quite happy with that kind of complexity, so if you belong to the "one-router-per-POP" school of thought the IGP complexity is a non-issue. --vadim

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Re: FIBER: CA, KS, LA, TX fiber cuts
by Sean Donelan 27 May '99

27 May '99

Fiber cut digest report for May 27, 1999 Hallsville, TX 9:30am CDT ???, LA 10:00am CDT Fairfax County, KS 2:35pm CDT Long Beach, CA 5:00pm CDT -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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FIBER: KS, LA, TX fiber cuts
by Sean Donelan 27 May '99

27 May '99

Fiber cut digest report for May 27, 1999 Hallsville, TX 9:30am CDT ???, LA 10:00am CDT Fairfax County, KS 2:35pm CDT -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation

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