The Cidr Report

Mailman List Mirror (Read Only)
1

This report has been generated at Fri Nov 12 21:44:35 2004 AEST.
The report analyses the BGP Routing Table of an AS4637 (Reach) router
and generates a report on aggregation potential within the table.

Check http://www.cidr-report.org/as4637 for a current version of this report.

Recent Table History
        Date Prefixes CIDR Agg
        05-11-04 156315 103806
        06-11-04 156228 103992
        07-11-04 156318 103854
        08-11-04 156312 102177
        09-11-04 148311 102028
        10-11-04 148405 102407
        11-11-04 148646 102468
        12-11-04 148794 102646

AS Summary
         18360 Number of ASes in routing system
          7492 Number of ASes announcing only one prefix
          1406 Largest number of prefixes announced by an AS
                AS7018 : ATTW AT&T WorldNet Services
      86853120 Largest address span announced by an AS (/32s)
                AS721 : DNIC DoD Network Information Center

Aggregation Summary
The algorithm used in this report proposes aggregation only
when there is a precise match using the AS path, so as
to preserve traffic transit policies. Aggregation is also
proposed across non-advertised address space ('holes').

--- 12Nov04 ---
ASnum NetsNow NetsAggr NetGain % Gain Description

Table 148874 102650 46224 31.0% All ASes

AS18566 751 6 745 99.2% CVAD Covad Communications
AS4134 825 178 647 78.4% CHINANET-BACKBONE
                                               No.31,Jin-rong Street
AS4323 794 223 571 71.9% TWTC Time Warner Telecom
AS7018 1406 1002 404 28.7% ATTW AT&T WorldNet Services
AS6197 814 430 384 47.2% BNS-14 BellSouth Network
                                               Solutions, Inc
AS22773 401 17 384 95.8% CXA Cox Communications Inc.
AS27364 413 45 368 89.1% ARMC Armstrong Cable Services
AS701 1230 884 346 28.1% UU UUNET Technologies, Inc.
AS22909 412 81 331 80.3% CMCS Comcast Cable
                                               Communications, Inc.
AS6478 426 98 328 77.0% ATTW AT&T WorldNet Services
AS1239 930 620 310 33.3% SPRN Sprint
AS17676 372 63 309 83.1% JPNIC-JP-ASN-BLOCK Japan
                                               Network Information Center
AS9929 335 33 302 90.1% CNCNET-CN China Netcom Corp.
AS7843 497 208 289 58.1% ADELPH-13 Adelphia Corp.
AS4355 384 99 285 74.2% ERSD EARTHLINK, INC
AS4766 531 268 263 49.5% KIXS-AS-KR Korea Telecom
AS14654 261 6 255 97.7% WAYPOR-3 Wayport
AS21502 253 3 250 98.8% ASN-NUMERICABLE NUMERICABLE is
                                               a cabled network in France,
AS9443 358 109 249 69.6% INTERNETPRIMUS-AS-AP Primus
                                               Telecommunications
AS15557 361 121 240 66.5% LDCOMNET LDCOM NETWORKS
AS6140 370 133 237 64.1% IMPSA ImpSat
AS721 1023 792 231 22.6% DNIC DoD Network Information
                                               Center
AS2386 849 620 229 27.0% ADCS-1 AT&T Data
                                               Communications Services
AS25844 244 16 228 93.4% SASMFL-2 Skadden, Arps, Slate,
                                               Meagher & Flom LLP
AS1221 801 578 223 27.8% ASN-TELSTRA Telstra Pty Ltd
AS6198 435 221 214 49.2% BNS-14 BellSouth Network
                                               Solutions, Inc
AS4814 208 6 202 97.1% CHINA169-BBN CNCGROUP IP
                                               network��China169 Beijing
                                               Broadband Network
AS5668 414 223 191 46.1% CIH-12 CenturyTel Internet
                                               Holdings, Inc.
AS15270 226 36 190 84.1% PDP-14 PaeTec.net -a division
                                               of PaeTecCommunications, Inc.
AS6517 300 116 184 61.3% YIPS Yipes Communications,
                                               Inc.

Total 16624 7235 9389 56.5% Top 30 total

Possible Bogus Routes

        24.138.80.0/20 AS11260 AHSICHCL Andara High Speed Internet c/o Halifax Cable Ltd.
        24.246.0.0/17 AS7018 ATTW AT&T WorldNet Services
        24.246.38.0/24 AS25994 NPGCAB NPG Cable, INC
        24.246.128.0/18 AS7018 ATTW AT&T WorldNet Services
        64.46.27.0/24 AS8674 NETNOD-IX Netnod Internet Exchange Sverige AB
        64.57.160.0/19 AS3561 CWU Cable & Wireless USA
        64.92.128.0/19 AS3561 CWU Cable & Wireless USA
        64.127.0.0/18 AS7018 ATTW AT&T WorldNet Services
        64.209.192.0/18 AS3561 CWU Cable & Wireless USA
        69.26.32.0/19 AS17307 VIRTEL-15 Virtela Communications
        132.0.0.0/10 AS721 DNIC DoD Network Information Center
        137.0.0.0/13 AS721 DNIC DoD Network Information Center
        138.136.0.0/13 AS721 DNIC DoD Network Information Center
        158.0.0.0/13 AS721 DNIC DoD Network Information Center
        192.30.93.0/24 AS17757 HPAUS-AP HP Australia
        192.30.94.0/24 AS17757 HPAUS-AP HP Australia
        192.30.127.0/24 AS719 LANLINK Elisa Oyj
        192.40.105.0/24 AS5515 SONERA-GLOBAL-IP Sonera Solution Autonomous System
        192.44.0.0/19 AS702 AS702 MCI EMEA - Commercial IP service provider in Europe
        192.70.164.0/24 AS25689 NRCC-2 National Research Council of Canada
        192.81.182.0/24 AS719 LANLINK Elisa Oyj
        192.81.183.0/24 AS719 LANLINK Elisa Oyj
        192.81.184.0/24 AS719 LANLINK Elisa Oyj
        192.119.135.0/24 AS270 NASA National Aeronautics and Space Administration
        192.124.252.0/22 AS680 DFN-IP service G-WiN
        192.133.6.0/24 AS4004 GLOBALONE-EQUANT-UK Equant UK & Greece Autonomous System
        192.135.50.0/24 AS7018 ATTW AT&T WorldNet Services
        192.153.144.0/21 AS721 DNIC DoD Network Information Center
        192.172.0.0/19 AS721 DNIC DoD Network Information Center
        192.188.208.0/20 AS721 DNIC DoD Network Information Center
        192.243.32.0/23 AS2044 PALINA Palin Aquisitions Inc.
        196.2.95.0/24 AS8668 TELONE-AS TelOne Zimbabwe P/L
        198.23.26.0/24 AS4390 BELLAT-7 Bell Atlantic, Inc.
        198.97.72.0/21 AS721 DNIC DoD Network Information Center
        198.97.80.0/20 AS721 DNIC DoD Network Information Center
        198.97.88.0/24 AS89 NUSC-1 Naval Underwater Systems Center
        198.97.240.0/20 AS721 DNIC DoD Network Information Center
        198.97.247.0/24 AS3475 DEPART-52 Department of the Navy
        198.101.4.0/22 AS721 DNIC DoD Network Information Center
        198.136.32.0/20 AS19329 MCBCC Martin County Board of County Commissioners
        198.144.32.0/19 AS3998 CITY CityNet, Inc.
        198.161.87.0/24 AS6539 GTGR GT Group Telecom Services Corp.
        198.161.165.0/24 AS852 AGTA Telus Advanced Communications
        198.163.155.0/24 AS684 MRN Manitoba Regional Network
        198.167.0.0/16 AS7456 INS-51 Interhop Network SERVICES Inc.
        198.167.163.0/24 AS15290 ACCA-2 Allstream Corp. Corporation Allstream
        198.168.0.0/16 AS701 UU UUNET Technologies, Inc.
        198.169.0.0/16 AS803 SASK SaskTel
        198.232.133.0/24 AS23075 SKOTOS Skotos Tech, Inc
        199.10.0.0/16 AS721 DNIC DoD Network Information Center
        199.60.0.0/20 AS271 UBC-3 University of British Columbia
        199.96.44.0/23 AS19092 360NE-1 360Networks (USA) Inc.
        199.96.46.0/24 AS19092 360NE-1 360Networks (USA) Inc.
        199.114.0.0/18 AS568 DISOUN DISO-UNRRA
        199.114.0.0/21 AS721 DNIC DoD Network Information Center
        199.114.128.0/18 AS721 DNIC DoD Network Information Center
        199.114.130.0/24 AS721 DNIC DoD Network Information Center
        199.114.132.0/24 AS721 DNIC DoD Network Information Center
        199.114.134.0/24 AS1913 DLA-8 Defense Logistics Agency
        199.114.136.0/24 AS1913 DLA-8 Defense Logistics Agency
        199.114.138.0/24 AS721 DNIC DoD Network Information Center
        199.114.140.0/24 AS3544 DISAUN DISA/UNRRA
        199.114.142.0/24 AS721 DNIC DoD Network Information Center
        199.114.148.0/24 AS721 DNIC DoD Network Information Center
        199.114.150.0/24 AS721 DNIC DoD Network Information Center
        199.114.152.0/24 AS1913 DLA-8 Defense Logistics Agency
        199.114.154.0/24 AS1733 ADP-41 AF DDN PMO
        199.114.156.0/24 AS1913 DLA-8 Defense Logistics Agency
        199.114.160.0/24 AS1733 ADP-41 AF DDN PMO
        199.120.32.0/19 AS16582 NXLI NEXTLEVEL INTERNET, INC.
        199.121.0.0/16 AS721 DNIC DoD Network Information Center
        199.123.0.0/18 AS721 DNIC DoD Network Information Center
        199.123.16.0/20 AS721 DNIC DoD Network Information Center
        199.123.80.0/21 AS721 DNIC DoD Network Information Center
        199.189.32.0/19 AS7332 IQUEST IQuest Internet
        199.197.8.0/22 AS21814 PARSON-18 Parsons Corp.
        199.202.0.0/16 AS701 UU UUNET Technologies, Inc.
        202.47.1.0/24 AS7491 PI-PH-AS-AP PI-PHILIPINES
        202.70.28.0/24 AS4515 ERX-STAR Star Internet Services Ltd.
        202.72.64.0/21 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.64.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.65.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.66.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.67.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.68.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.69.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.70.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.71.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.72.0/21 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.72.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.73.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.74.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.75.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.76.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.77.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.78.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.72.79.0/24 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        202.73.128.0/22 AS4058 LINKAGENET-AP CPCNet Hong Kong Ltd.
        202.93.0.0/20 AS4134 CHINANET-BACKBONE No.31,Jin-rong Street
        202.160.128.0/23 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.131.0/24 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.132.0/22 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.136.0/22 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.142.0/24 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.144.0/24 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.145.0/24 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.146.0/24 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.147.0/24 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.148.0/22 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.156.0/23 AS9282 LEXICON-AS Lexicon Systems Pty Ltd
        202.160.158.0/23 AS17642 RDSL-NATIONAL-AS Request Broadband BGP AS number
        202.164.128.0/19 AS9654 CYBERSPACE-AP P/H Padilla Bldg., Emerald Avenue
        202.164.224.0/19 AS7599 IPXC-AS-AP IP Exchange
        203.32.4.0/23 AS7617
        203.62.0.0/17 AS7572 AARNET-ACT-RNO Australian Academic and Reasearch Network (AARNet)
        203.84.192.0/19 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        203.84.192.0/20 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        203.84.208.0/20 AS17433 PHILWEB-AP PhilWeb.Com, Inc.
        203.99.0.0/19 AS17746 ORCONINTERNET-NZ-AP Orcon Internet
        203.170.14.0/23 AS6648 ASN-SKYINTERNET Autonomous System Number peering of Sky Internet - BAYANTEL Inc. - Philppines
        203.210.69.0/24 AS17536 PRODIGY-AS-AP Prodidgy Telecommunications
        204.154.125.0/24 AS3952 TELLAB-1 TELLABS Operations, Inc.
        204.154.126.0/24 AS3952 TELLAB-1 TELLABS Operations, Inc.
        204.154.127.0/24 AS3952 TELLAB-1 TELLABS Operations, Inc.
        204.194.110.0/23 AS30653 EXOBI Exobit Networks Inc.
        205.150.0.0/15 AS701 UU UUNET Technologies, Inc.
        206.167.57.0/24 AS376 RISQR-3 Reseau Interordinateurs Scientique Quebecois (RISQ)
        206.191.64.0/18 AS15290 ACCA-2 Allstream Corp. Corporation Allstream
        206.251.69.0/24 AS27429 TIL-33 Telesat International Ltd.
        206.253.190.0/23 AS8123 POLYBA Polybase
        207.47.254.0/24 AS701 UU UUNET Technologies, Inc.
        207.231.96.0/19 AS11194 NUNETI NuNet Inc
        208.81.187.0/24 AS19194 SNL-8 Sentris Network LLC
        209.172.0.0/18 AS7770 TRTI Triton Technologies, Inc.
        209.205.69.0/24 AS21578 Universidad autonoma de Bucaramanga
        209.205.70.0/24 AS21578 Universidad autonoma de Bucaramanga
        209.205.81.0/24 AS15066 SkyNet de Colombia S.A.
        209.205.82.0/24 AS15066 SkyNet de Colombia S.A.
        209.205.84.0/24 AS15066 SkyNet de Colombia S.A.
        209.213.32.0/19 AS10629 INS-52 Inter-Pacific Network Services
        209.213.48.0/24 AS10629 INS-52 Inter-Pacific Network Services
        209.213.49.0/24 AS10629 INS-52 Inter-Pacific Network Services
        209.213.50.0/24 AS10629 INS-52 Inter-Pacific Network Services
        209.251.0.0/19 AS11036 SISCOM-1 SISCOM, Inc
        216.37.110.0/23 AS4264 CERFN California Education and Research Federation Network
        216.96.128.0/18 AS7018 ATTW AT&T WorldNet Services
        216.145.156.0/24 AS20304 JIS-32 JVLNET Internet Services
        216.145.158.0/24 AS20304 JIS-32 JVLNET Internet Services
        216.145.176.0/21 AS20304 JIS-32 JVLNET Internet Services
        216.145.177.0/24 AS20304 JIS-32 JVLNET Internet Services
        216.145.178.0/24 AS20304 JIS-32 JVLNET Internet Services
        216.145.184.0/21 AS10758 INWAVE INWave Internet, Inc
        216.145.200.0/21 AS20304 JIS-32 JVLNET Internet Services
        216.171.96.0/20 AS3356 LEVEL3 Level 3 Communications
        216.186.151.0/24 AS3356 LEVEL3 Level 3 Communications
        216.186.152.0/21 AS3356 LEVEL3 Level 3 Communications
        216.186.160.0/23 AS3356 LEVEL3 Level 3 Communications
        216.186.164.0/22 AS3356 LEVEL3 Level 3 Communications
        216.186.192.0/22 AS3356 LEVEL3 Level 3 Communications
        216.186.198.0/23 AS3356 LEVEL3 Level 3 Communications
        216.186.248.0/23 AS3356 LEVEL3 Level 3 Communications

Please see http://www.cidr-report.org for the full report

2

ASnum NetsNow NetsAggr NetGain % Gain Description

AS18566 751 6 745 99.2% CVAD Covad Communications
AS4134 825 178 647 78.4% CHINANET-BACKBONE
                                               No.31,Jin-rong Street
AS4323 794 223 571 71.9% TWTC Time Warner Telecom
AS6197 814 430 384 47.2% BNS-14 BellSouth Network
                                               Solutions, Inc
AS22773 401 17 384 95.8% CXA Cox Communications Inc.
AS27364 413 45 368 89.1% ARMC Armstrong Cable Services
AS701 1230 884 346 28.1% UU UUNET Technologies, Inc.
AS22909 412 81 331 80.3% CMCS Comcast Cable
                                               Communications, Inc.

are these numbers what i think, but hope not, they are?

e.g. is AS18566 the origin AS for 751 prefixes that could be
collapsed to 6?

if not, then perhaps the report could use some work.

if so, then
  o why are providers indulging is such extremely sick
    behavior
  o and who can hack the perl to generate filters for this
    so we can listen only to the aggregates

randy

3

not to justify the expense, but perhaps covad is renumbering from one
block to another? Looking at their advertisments I see lots of /23 or /24
blocks inside their larger covering routes... So either they deaggregated
to renumber more gracefully, or they forgot their prefix-list outbound to
williams and exodus ?

perhaps covad can explain? or silently cover up the 'mistake' (which is
acceptable as well...)

4

> ASnum NetsNow NetsAggr NetGain % Gain Description
>
> AS18566 751 6 745 99.2% CVAD Covad Communications

are these numbers what i think, but hope not, they are?

e.g. is AS18566 the origin AS for 751 prefixes that could be
collapsed to 6?

  Sort of - from here it looks like they aren't actually announcing
the supernets.

  o and who can hack the perl to generate filters for this
    so we can listen only to the aggregates

  I don't see their stuff listed in the radb, so it looks like you
have to go to the router itself to read the routes to determine what they
are announcing, then ask the appropriate registry which block they
are announcing from, aggregate the routes in that block, rinse and repeat,
aggregate the aggregated blocks, then filter.
  ..but that only works if they announce the supernets. Without that
I'm not sure what you can do that wouldn't end up biting you back. It's also
a lot of work for not too much reward as long as these messes are the
exception and not the rule.

  Plus the public hand slap is kind of amusing. But that's probably
just me.

  Austin

5

> > ASnum NetsNow NetsAggr NetGain % Gain Description
> >
> > AS18566 751 6 745 99.2% CVAD Covad Communications

> are these numbers what i think, but hope not, they are?
>
> e.g. is AS18566 the origin AS for 751 prefixes that could be
> collapsed to 6?

  Sort of - from here it looks like they aren't actually announcing
the supernets.

So you don't see:
64.105.0.0/16
66.134.0.0/16
66.166.0.0/15
67.100.0.0/14
68.164.0.0/14
69.3.0.0/16

?

I don't see their stuff listed in the radb,

They actually did register all that more-specific crap (determined by
checking some 10 samples), so they do this fully intentional.

Well, it boils down that if you have enough customers, you seem to
get away with about any antisocial behaviour on the net.

Plus the public hand slap is kind of amusing. But that's probably
just me.

The problem is that they probably couldn't care less. There is no
public sanctioning and pressure.

Regards,
Daniel

6

ASnum NetsNow NetsAggr NetGain % Gain Description

AS18566 751 6 745 99.2% CVAD Covad Communications
AS4134 825 178 647 78.4% CHINANET-BACKBONE
                                               No.31,Jin-rong Street
AS4323 794 223 571 71.9% TWTC Time Warner Telecom
AS6197 814 430 384 47.2% BNS-14 BellSouth Network
                                               Solutions, Inc
AS22773 401 17 384 95.8% CXA Cox Communications Inc.
AS27364 413 45 368 89.1% ARMC Armstrong Cable Services
AS701 1230 884 346 28.1% UU UUNET Technologies, Inc.
AS22909 412 81 331 80.3% CMCS Comcast Cable
                                               Communications, Inc.

e.g. is AS18566 the origin AS for 751 prefixes that could be
collapsed to 6?

not to justify the expense, but perhaps covad is renumbering from one
block to another? Looking at their advertisments I see lots of /23 or /24
blocks inside their larger covering routes... So either they deaggregated
to renumber more gracefully, or they forgot their prefix-list outbound to
williams and exodus ?

perhaps covad can explain? or silently cover up the 'mistake' (which is
acceptable as well...)

it's not just covad. they're just such an egregious case among
many socially and technically irresponsible polluters.

randy

7

> > > ASnum NetsNow NetsAggr NetGain % Gain Description
> > >
> > > AS18566 751 6 745 99.2% CVAD Covad Communications
>
> > are these numbers what i think, but hope not, they are?
> >
> > e.g. is AS18566 the origin AS for 751 prefixes that could be
> > collapsed to 6?
>
> Sort of - from here it looks like they aren't actually announcing
> the supernets.

So you don't see:
64.105.0.0/16
66.134.0.0/16
66.166.0.0/15
67.100.0.0/14
68.164.0.0/14
69.3.0.0/16

?

there are still places on the net that do odd-ball filtering... perhaps he
lives in one? (or nets from one?) (he being austin...)

> Plus the public hand slap is kind of amusing. But that's probably
> just me.

The problem is that they probably couldn't care less. There is no
public sanctioning and pressure.

and like I said, they MIGHT have a valid reason for this. I seem to
remember a cable company a few months back doing this during a renumber,
or some migration... I was hoping Covad would stand up, or someone who
knows more (and has less of an axe to grind?), and set the record
straight.

Or, 'just make it go away' and leave randy/daniel/austin to wonder what
happened :slight_smile: Either way, so long as it stops, right?

8

eh, since I singled out covad: (and I feel bad for it now)
what about for COX? what about for UU (doh, thats me...or our tac or
something, I'll look/ask), what about Comcast? and TWTC? ArmStrong?

Of these listed 4 are cable companies, is there something in the cable
modem networking that requires deaggregated routes beyond their borders?
Is the problem that they might have seperate 'networks' for their regional
parts and leak more specifics for these parts along with 'backup' routes
via aggregates?

-Chris

9

eh, since I singled out covad: (and I feel bad for it now)
what about for COX? what about for UU (doh, thats me...or our tac or
something, I'll look/ask)

thanks!

randy

10

Daniel Roesen writes:

Well, it boils down that if you have enough customers, you seem to
get away with about any antisocial behaviour on the net.

You don't need to have many customers, it's just more fun if you have
a larger space that you can deaggregate. Since everybody stopped
filtering you can deaggregate everything into /24s today and get away
with it. So as soon as you have a /23 you can play. And there are
just too many "valid reasons" to resist.

Around here most ISPs, when they announce new customer routes, send
mail to their peers saying "we will announce these prefixes under
these paths, please update your filters". I often respond with a
friendly note that we will filter this or that prefix because it's a
more specific of a PA prefix (which we will actually do, although it
doesn't matter that much since we always have a fallback). Sometimes
I offer to put in a temporary (usually a year) filter exception so
that they can renumber their new customer into aggregatable space.

It doesn't help often, but sometimes it does.
"Think globally, act locally."

11

[snip]

Of these listed 4 are cable companies, is there something in the cable
modem networking that requires deaggregated routes beyond their borders?

No, for the general statement about 'cable modem networking'.

Is the problem that they might have seperate 'networks' for their regional
parts and leak more specifics for these parts along with 'backup' routes
via aggregates?

This is trivial to do only as far as your $s carry. Aggregate draws
the traffic, then NO_EXPORT-tagged longest-match carries the
regionalized traffic. Folks do this as a 'best exit' approach between
peer netwworks all the time. If you are suggesting disjoint, unconnected
islands, then they should be separate ASNs for sane paths; see charter's
islands, the pre-271 refleif ILEC LATA-bound islands, etc.

12

You have jumped to the conclusion that a customer of the cable company is
not multi-homed. Bad assumption. I can tell you that there are multihomed
customers behind what you would normally think of as a cable company.

Roy Engehausen

13

> ASnum NetsNow NetsAggr NetGain % Gain Description
>
> AS18566 751 6 745 99.2% CVAD Covad Communications
> AS4134 825 178 647 78.4% CHINANET-BACKBONE
> No.31,Jin-rong Street
> AS4323 794 223 571 71.9% TWTC Time Warner Telecom
> AS6197 814 430 384 47.2% BNS-14 BellSouth Network
> Solutions, Inc
> AS22773 401 17 384 95.8% CXA Cox Communications Inc.
> AS27364 413 45 368 89.1% ARMC Armstrong Cable Services
> AS701 1230 884 346 28.1% UU UUNET Technologies, Inc.
> AS22909 412 81 331 80.3% CMCS Comcast Cable
> Communications, Inc.

are these numbers what i think, but hope not, they are?

e.g. is AS18566 the origin AS for 751 prefixes that could be
collapsed to 6?

Barry and me tried:
http://www.nanog.org/mtg-0302/cidr.html

Covad was first contacted Aug 2002:

ASnum NetsNow NetsCIDR NetGain % Gain Description
AS18566 264 4 260 98.5% COVAD Covad Communications

But Covad was just one. I used to quietly contact these "pollutors" along with a few others who helped out (Barry and Terry) but as of a year ago I'm giving my 5-10 hours of volunteerism per month to nsp-sec.

-Hank

14

You have assumed that they assumed. Bad assumption.

Most of those deaggregated CIDRs do not show up behind any other AS. Nor are they in another AS.

If they are multi-homed, at least one, and hopefully both of those properties would hold.

15

> ASnum NetsNow NetsAggr NetGain % Gain Description
>
> AS18566 751 6 745 99.2% CVAD Covad Communications

are these numbers what i think, but hope not, they are?

e.g. is AS18566 the origin AS for 751 prefixes that could be
collapsed to 6?

yup - see AS Report

if not, then perhaps the report could use some work.

I'm more than happy to do further work on this report to improve its accuracy and helpfulness to the operator community, but in this case I'm not sure what such work would be, as I believe that the report is accurate about the potential level of prefix removal at a global BGP level.

Geoff

16

> e.g. is AS18566 the origin AS for 751 prefixes that could be
> collapsed to 6?
>

        Sort of - from here it looks like they aren't actually announcing
the supernets.

The covering /162, /15 and /14 aggregates are being globally announced, and the more specifics are being announced from the same origin AS, apparently along the same AS paths as the specifics, so its not clear that there is any form of traffic engineering or load balancing going on.

regards,

    Geoff

17

You have jumped to the conclusion that a customer of the cable company is
not multi-homed. Bad assumption. I can tell you that there are multihomed
customers behind what you would normally think of as a cable company.

I'm not sure I did jump to that conclusion, and most (all?) of the
prefixes I looked at (quickly as they scrolled) had an originating ASN of
18665 or whichever was covad. Either way, that would account for a few,
not all, of their deaggregated routes.