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New Member

Community issue

Hi all

I have 2 links to differnet ISP's, we have implemented a blackhole routing.I can advertise routes tagged with communities specified by my upsteam providers, but the problem is when i advertise a route with community speicifed by ISP-1 it is advertised to ISP-2 too.What is yor suggestions how can i prevent advertisment of routes tagged by community assigned by isp-1 to appear on ISP-2.

Thx.

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Re: Community issue

You are probably configuring the route-map on the network statement, right? You should apply the route-map outbound on the specific ISP as follow:

router bgp xxx

neighbor ISP1 route-map ISP1 out

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
4 REPLIES
Purple

Re: Community issue

At what point are you attaching communties to your routes ? Is it when you redistribute the routes into BGP ? It might be better to use an outbound route-map on each of your BGP sessions and then apply the community there.

Hope that helps - pls rate the post if it does.

Paresh

New Member

Re: Community issue

The way I am doing this is :

route-map DDOS permit 10

set community 60:10

router bgp xxx

network xx.xx.xx.xx mask 255.255.255.255 route-map DDOS

Cisco Employee

Re: Community issue

you should add a match ip address statement in the route-map for the specific prefix and apply it outbound using the neighbot statement.

router bgp xxx

neighbor ISP1 route-map DDOS out

neighbor ISP1 send-community

route-map DDOS permit 10

match ip address 1

set community 60:10

access-list 1 permit xx.xx.xx.xx

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
Cisco Employee

Re: Community issue

You are probably configuring the route-map on the network statement, right? You should apply the route-map outbound on the specific ISP as follow:

router bgp xxx

neighbor ISP1 route-map ISP1 out

Hope this helps,

Harold Ritter
Sr. Technical Leader
CCIE 4168 (R&S, SP)
harold@cisco.com
México móvil: +52 1 55 8312 4915
Cisco México 
Paseo de la Reforma 222 Piso 19
Cuauhtémoc, Juárez
Ciudad de México, 06600
México
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