All things related to multicast

[Gordon Rogier <>]

I believe that the msdp  in AS1741 and AS2831 (and there may be
others) is misconfigured.  We have been seeing problems with msdp
announcements from within our sites.  One of our sites is advertizing a
session via sdr, but we are seeing the msdp sa announcements as comming
from AS1741 or AS2831. (see some detail from a router on the path in our
topology).

The main problem is that these RPs (130.240.22.190 & 193.166.5.252) are
_NOT_ the real RP for this source!!  I suspect that these RP/MSDP speakers
are misconfigured with some sort of msdp redistribute or something like
this......

We did a little analysis and this is _roughly_ what we are seeing;
someone can easily critique the exact detail of the mroute/mdsp
conflicts, but in essesence the msdp topology is corrupted by these
rogue msdp speakers.

The first msdp announcement does get out of this site, NDSU, and heads out
as the correct msdp announment to the world (and I can see it correctly in
along this path in my router ks-2.r).  Now, in a short period (~30secs), I
see another msdp announcement from AS1740 or AS2831 saying they are the
RP. ks-2.r passes this back to the site NDSU.  The NDSU msdp router sees
this (S,G) SA message and marks the corresponding (S,G) mroute with an
msdp flag.  In doing this, it also causes the NDSU msdp speaker to _STOP_
sending SA messages for this (S,G) pair.  Now the topology (even the NDSU
part) thinks that the RP for this (S,G) is in AS1741 or AS2831
respectively.


ks-2.r>sh clock
08:43:39.715 CST Wed Dec 1 1999

ks-2.r>sh ip msdp sa-cache 224.2.247.48
MSDP Source-Active Cache - 1103 entries
(134.129.125.158, 224.2.247.48), RP 130.240.22.190, MBGP/AS 2831, 
02:11:15/00:05:46
(130.230.16.218, 224.2.247.48), RP 193.166.5.252, MBGP/AS 1741, 
01:36:02/00:04:59
(128.214.38.132, 224.2.247.48), RP 193.166.5.252, MBGP/AS 1741, 
01:35:02/00:05:59
(130.231.20.10, 224.2.247.48), RP 193.166.5.252, MBGP/AS 1741, 
01:35:02/00:05:59
(130.231.240.37, 224.2.247.48), RP 193.166.5.252, MBGP/AS 1741, 
01:35:02/00:05:59
(193.167.224.15, 224.2.247.48), RP 193.166.5.252, MBGP/AS 1741, 
01:35:02/00:05:59

ks-2.r>sh ip sdr "window on NDSU"
SDR Cache - 85 entries
Session Name: window on NDSU
  Description: View from IACC
  Group: 0.0.0.0, ttl: 0, Contiguous allocation: 1
  Lifetime: from 08:00:00 CST Nov 8 1999 until 08:00:00 CST Dec 6 1999
  Uptime: 3w2d, Last Heard: 00:01:58
  Announcement source: 134.129.125.158, destination: 224.2.127.254
  Created by: juell 3151059585 3151246623 IN IP4 ruby.cs.ndsu.nodak.edu
  Phone number:  701 231-8196
  Email:  <Paul Juell>
  URL:
  Media: audio 27174 RTP/AVP 0
    Media group: 224.2.230.122, ttl: 63
    Attribute: ptime:40
  Media: video 61162 RTP/AVP 31
    Media group: 224.2.247.48, ttl: 63

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Gordon Rogier                        

            
Network Engineer                     785-864-0381wk 785-550-4468 cell
Great Plains Network                 785-864-9330 FAX