At 19:28 18/06/01 -0400, Marshall Eubanks wrote:

Hello All;

We had a problem with a domain with two different AS paths in the BGP table, so I wrote a script to look for such problems.

There are two prefixes in the current MBGP tables here with such problems :

Go to route-views.oregon-ix.net: route-views.oregon-ix.net>sho ip mbgp sum | excl NoNeg|Active BGP router identifier 198.32.162.100, local AS number 6447 MBGP table version is 552946 4874 network entries and 29094 paths using 1500666 bytes of memory 658329 BGP path attribute entries using 34233108 bytes of memory 504166 BGP AS-PATH entries using 12495820 bytes of memory 408 BGP community entries using 10324 bytes of memory 27226 BGP filter-list cache entries using 435616 bytes of memory Dampening enabled. 62 history paths, 3305 dampened paths BGP activity 391384/274126 prefixes, 54115708/50018963 paths Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 129.250.0.6 4 2914 1974401 36393 552946 0 0 4d09h 3936 129.250.0.11 4 2914 1378596 36399 552946 0 0 1w6d 3936 155.229.0.36 4 4565 122639 30255 552946 0 0 1w5d 23 198.32.8.252 4 11537 136322 36119 552946 0 0 1w3d 3543 203.181.248.242 4 7660 189814 71618 552946 0 0 05:34:54 1863 204.42.253.253 4 267 1251009 36379 552946 0 0 1w6d 3941 204.212.44.131 4 234 979924 36399 552946 0 0 1w6d 3938 205.215.45.50 4 4006 3332093 55271 552946 0 0 5d16h 2738 206.220.240.222 4 10764 2326042 69592 552946 0 0 05:33:12 4760 216.140.2.63 4 6395 1776339 36347 552946 0 0 4d20h 118 216.140.8.63 4 6395 1598580 36337 552946 0 0 4d20h 118 216.140.14.127 4 6395 1631400 36135 552946 0 0 3d19h 118 A simple count via: route-views.oregon-ix.net>sho ip mbgp inc | incl > Status codes: s suppressed, d damped, h history, * valid, > best, i - internal *> 129.250.0.11 5 0 2914 3549 i *> 206.220.240.222 0 10764 145 195 i *> 206.220.240.222 0 10764 145 195 i *> 206.220.240.222 0 10764 145 195 i *> 129.250.0.6 22 0 2914 i *> 129.250.0.11 16 0 2914 1800 i *> 129.250.0.6 22 0 2914 i *> 129.250.0.11 16 0 2914 i *> 129.250.0.11 16 0 2914 i *> 129.250.0.11 9 0 2914 i *> 129.250.0.11 12 0 2914 i *> 129.250.0.11 5 0 2914 i *> 129.250.0.11 8 0 2914 i *> 129.250.0.11 9 0 2914 i *> 206.220.240.222 0 10764 145 195 i *> 206.220.240.222 0 10764 145 195 i shows 16 prefixes that are inconsistent AS origin within the MBGP tables (if anyone knows the reg-exp for seeing the actual prefixes - 1 per line and not just the best path - I'd like to know :-)). As we see in the larger BGP tables (close to 500 inconsistent ASs), not too many ISPs care about this. -Hank

Date of BGP Dump Mon Jun 18 15:39:46 EDT 2001

ROUTING INCONSISTENCY Detected for Prefix = 198.9.201.0 :

*> 198.9.201.0 160.81.38.225 75 0 1239 10888 i * 204.147.129.89 0 145 24 i

ROUTING INCONSISTENCY Detected for Prefix = 198.9.202.0 :

* 198.9.202.0 204.147.129.89 0 145 24 i *> 160.81.38.225 75 0 1239 10888 i

And a total of 488 prefixes in the BGP tables with such problems !!!!!

The complete lists are contained in

http://www.multicasttech.com/status/mbgp.inconsistency and http://www.multicasttech.com/status/bgp.inconsistency

I could update these regularly if there was any demand.

I may be obtuse, but I cannot see how this could be a good thing.

Regards Marshall Eubanks

T.M. Eubanks Multicast Technologies, Inc 10301 Democracy Lane, Suite 410 Fairfax, Virginia 22030 Phone : 703-293-9624 Fax : 703-293-9609 e-mail : tme@multicasttech.com http://www.on-the-i.com

Test your network for multicast : http://www.multicasttech.com/mt/ Check the status of multicast in real time : http://www.multicasttech.com/status/index.html