Also note there is nothing stopping anyone from adding any community
they want.
The effect and how long the community stays attached to a route is
another matter.
On 1/7/2015 8:35 AM, Song Li wrote:
Hi everyone,
Today when I check one route in Routeviews I find something strange as
follows:
route-views>sh ip bgp 176.108.0.0
BGP routing table entry for 176.108.0.0/19, version 23405621
Paths: (33 available, best #28, table default)
Not advertised to any peer
Refresh Epoch 1
202018 35320 35320 57800
5.101.110.2 from 5.101.110.2 (5.101.110.2)
Origin IGP, localpref 100, valid, external
Community: 702:120 2914:429 20485:52990 20485:53990 20485:54040
20485:54050 47541:10001
rx pathid: 0, tx pathid: 0
the AS-Path is "202018 35320 35320 57800" but the community is 702:120
2914:429 20485:52990 ....
According to RFC 1997, the community format is AA:NN and AA means the
AS#. Here, AS702, AS2914 and AS20485 do not appear in the AS-Path and
as a result they should not appear in the community. Could anybody
tell me what's the reason they do appear in the community of this route?
Thanks!
