Yes, I've tried that too.. But what I am thinking of doing is, using a route-map/bgp-announcement based version of building 'prefix-list' or 'distribute-list' to decide whether to accept route or not.. But as you said, I don't think that is possible heh.. Thanks! -hc -- Sincerely, Haesu C. TowardEX Technologies, Inc. WWW: http://www.towardex.com E-mail: haesu@towardex.com Cell: (978) 394-2867 On Mon, Aug 25, 2003 at 02:57:57PM -0400, ww@styx.org wrote:
I don't think what you are suggesting is directly possible, although I can think of something that accomplishes the same thing, and only requires extra configuration on the peering session with the route server.
For prefixes recieved from the bogon route server, apply a route map that will (1) send traffic to a Null0 bit sink and (2) set the local preference for these routes to a value suitably large so that the same prefixes learned from other peers never get used.
-w
On Mon, 25 Aug 2003 14:39:59 -0400, Haesu wrote
Hi all,
Wondering if anyone would know whether such feature in IOS exists or not...
Most of the time, people use route-maps on bgp neighbors or peer- groups to set an attribute,etc on a prefix that is being announced OUTbound or INbound.
However: On prefixes being announced to me INBOUND, is there a feature to set in route-map so that it checks whether the advertised prefix is already existing in local RIB?
Like for example, I am one of the users who receive bogon advertisements from Rob's route-server.
Now, when I receive prefixes either from my upstream AS or my customers doing bgp with me, I can setup a route-map on the neighbor so that it compares the prefix being announced by neighborAS with existing Rob's bogon prefix in the RIB with bogon route-server community 65333:888.
If the prefix being announced gets a match with existing prefix with 65333:888 already in the router, the route-map would cause a DENY. Thus, making Rob's bogon announcement from his route-server, a bogon route filtering list for me to use on my customers/peers..
If you are not understanding what I am saying, feel free to yell at me to clear up..
This would make it much easier to create dynamic bgp-based route filtering list in my opinion... I am not here to discuss the feasibility of whether doing or inventing this dynamic method of filtering bgp routes; I am rather asking this question to see if anyone is doing something similar to this as it may be useful.
Thanks!
-hc
-- Sincerely, Haesu C. TowardEX Technologies, Inc. WWW: http://www.towardex.com E-mail: haesu@towardex.com Cell: (978) 394-2867