Re: bgp route-map

[Haesu <haesu () towardex com>]

Of course; since there isn't a feature, let's propose another idea: an
option to enable "le 24" or "le 32/whatever" to cover specific
announcements.

-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 03:30:01PM -0400, Matt Levine wrote:
> 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 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
> --
> Matt Levine <matt () deliver3 com>
> "The Trouble with doing anything right the first time is that nobody 
> appreciates how difficult it was."  -BIX