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Re: bgp route-map

  • From: Haesu
  • Date: Mon Aug 25 15:45:56 2003

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: [email protected]
  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: [email protected]
> >  Cell: (978) 394-2867
> >
> >On Mon, Aug 25, 2003 at 02:57:57PM -0400, [email protected] 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: [email protected]
> >>>  Cell: (978) 394-2867
> >
> >
> --
> Matt Levine <[email protected]>
> "The Trouble with doing anything right the first time is that nobody 
> appreciates how difficult it was."  -BIX