[126511] in North American Network Operators' Group
RE: useful bgp example
daemon@ATHENA.MIT.EDU (Vincent C Jones)
Wed May 19 15:04:28 2010
Date: Wed, 19 May 2010 15:04:15 -0400
From: Vincent C Jones <v.jones@networkingunlimited.com>
In-reply-to: <B3520B5286C55F4480D8E43FDFE51D0F21957387@mailman2.faps.net>
To: Jeff Harper <jharper@first-american.net>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Wed, 2010-05-19 at 13:37 -0500, Jeff Harper wrote:
> > From: Jared Mauch [mailto:jared@puck.nether.net]
> > Sent: Wednesday, May 19, 2010 1:29 PM
> > To: Jeff Harper
> > Cc: Deric Kwok; nanog@nanog.org
> > Subject: Re: useful bgp example
> >
> > Nice, but you don't show it as-path filtering your transits out. I
> > frequently see people take something learned from transit A and
> sending
> > it to transit B, and if it happens to be the backup path in-use for
> > your customer, your transits will accept it and likely pick you as
> > best-path and hairpin through your network.
> >
> > - Jared
>
> Yeah, I left out the actual prefix-list contents, in hindsight I should
> have added it, so here it is. Also, a typo in the network statement,
> lol.
>
> network 1.1.1.0 mask 255.255.0.0
>
> ip prefix-list NETZ description The networks we advertise via BGP
> ip prefix-list NETZ seq 10 permit 1.1.1.0/16
> ip prefix-list NETZ seq 1000 deny 0.0.0.0/0 le 32
FYI: It's got to be either 1.1.1.0/24 or 1.1.0.0/16. And there is plenty
more that belongs in an appropriate setup for a realistic usage
scenario. This is why we are all advising the OP to get some
knowledgeable help.
Vince
--
Vincent C. Jones
Networking Unlimited, Inc.
Phone: +1 201 568-7810
V.Jones@NetworkingUnlimited.com
