bgp route-map
Haesu
haesu at towardex.com
Mon Aug 25 19:00:45 UTC 2003
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 at towardex.com
Cell: (978) 394-2867
On Mon, Aug 25, 2003 at 02:57:57PM -0400, ww at 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 at towardex.com
> > Cell: (978) 394-2867
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