Filtering BGP networks with access list

Jun 23, 2010 2 Replies

Hi, I currently advertise 4 /24s through BGP. I have my distribute list set up as an access list:



access-list 110 permit ip xxx.xxx.184.0 0.0.0.255 any access-list 110 permit ip xxx.xxx.185.0 0.0.0.255 any access-list 110 permit ip xxx.xxx.186.0 0.0.0.255 any access-list 110 permit ip xxx.xxx.187.0 0.0.0.255 any



I am trying to turn up a "virtual circuit" with one of my ISPs that will be routing part of one of these networks to a remote site. Obviously, because of this, I must stop announcing this network through BGP with them.



If this network is xxx.xxx.187.48/30, what is the best way to filter it out of the BGP advertisements? Can I just add: access-list 110 deny ip host xxx.xxx.187.48 host 255.255.255.252 to the beginning of my access list? Or do I have to do something more complicated?



Thanks.


-- James


snipped-for-privacy@gmail.com said the following on 23/06/2010 02:11:

isn't xxx.xxx.187.48/30 included in xxx.xxx.187.0/24 ?

am I dumb?

Daniel-G said the following on 06/25/2010 03:39 PM:

I'd better read twice before answering yes deny will do it, you saw already I guess

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