nanog mailing list archives
Re: bgp route-map
From: Matt Levine <matt () deliver3 com>
Date: Mon, 25 Aug 2003 15:30:01 -0400
On Monday, August 25, 2003, at 3:00 PM, Haesu wrote:
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..
Except that what you are proposing would allow your customer to announce 2 /16's just fine from within one of rob's bogon /8's, as the 2 /16's wouldn't be in your rib.
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 onthe 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 getused. -w On Mon, 25 Aug 2003 14:39:59 -0400, Haesu wroteHi 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
-- Matt Levine <matt () deliver3 com>"The Trouble with doing anything right the first time is that nobody appreciates how difficult it was." -BIX
Current thread:
- bgp route-map Haesu (Aug 25)
- Re: bgp route-map ww (Aug 25)
- Re: bgp route-map Haesu (Aug 25)
- Re: bgp route-map Matt Levine (Aug 25)
- Re: bgp route-map Haesu (Aug 25)
- Re: bgp route-map E.B. Dreger (Aug 25)
- Re: bgp route-map Cliff Albert (Aug 25)
- Re: bgp route-map Haesu (Aug 25)
- Re: bgp route-map ww (Aug 25)
- Route Programming (was Re: bgp route-map) Leo Bicknell (Aug 25)
- Re: Route Programming (was Re: bgp route-map) Haesu (Aug 25)
- Lazy Engineers and Viable Excuses Danny McPherson (Aug 25)
- Re: Lazy Engineers and Viable Excuses Rob Thomas (Aug 25)
- Re: Lazy Engineers and Viable Excuses Haesu (Aug 25)
- Re: Lazy Engineers and Viable Excuses Joe Abley (Aug 25)
- Re: Lazy Engineers and Viable Excuses Jared Mauch (Aug 25)
- Re: Route Programming (was Re: bgp route-map) Haesu (Aug 25)