[j-nsp] Need help with stripping of BGP communities

[Eric Van Tol]

> -----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net [mailto:juniper-nsp-
> bounces at puck.nether.net] On Behalf Of Alexander Shikoff
> Sent: Tuesday, October 06, 2009 1:52 PM
> To: juniper-nsp
> Subject: [j-nsp] Need help with stripping of BGP communities
> 
> Hello All,
> 
> I have M10i router and need to strip BGP communities that don't match
> regex
> pattern.
> 
> I've configured BGP community:
> [edit policy-options]
> minotaur at br1-gdr.ki# show community Prohibited
> invert-match;
> members "^((9002)|(21011)|(13228)):([0-5])$";
> 
> Then I've created policy-statement and applied it to neighbour's import:
> [edit]
> minotaur at br1-gdr.ki# show policy-options policy-statement from-Downstream
> then {
>     community delete Prohibited;
>     next policy;
> }
> 
> [edit]
> minotaur at br1-gdr.ki# show protocols bgp group Downlinks-Default-Only
> neighbor 91.200.195.18
> description "Downlink: UOS";
> import [ from-Downstream from-UOS ];
> peer-as 42546;
> 
> But communities that don't match "^((9002)|(21011)|(13228)):([0-5])$" are
> still associated with prefixes that I receive from downstream:
> 
> * 91.202.39.0/24 (2 entries, 1 announced)
>      Accepted
>      Nexthop: 91.200.195.18
>      AS path: 42546 42546 42546 42546 44532 44532 I
>      AS path: Recorded
>      Communities: 65535:1111 65535:9002
> 
> To my shame I cannot find an error in configuration...
> Any help will be heartly appreciated. Thanks.
> 
> --
> MINO-RIPE

What is the 'show route' command you are using to get this information?  AFAIK, 'show route receive-protocol bgp' shows what is received, communities and all, prior to policy processing.  In order to see the routes that have passed through your policy, just do 'show route 91.202.39.0/24 detail' and those communities should not show up.

-evt