useful bgp example

Jian Gu guxiaojian at
Sat May 22 18:43:59 UTC 2010

You don't need

ip prefix-list NETZ seq 1000 deny le 32

You can use RFC1918 space address for iBGP peering.

On Wed, May 19, 2010 at 11:37 AM, Jeff Harper
<jharper at> wrote:
>> -----Original Message-----
>> From: Jared Mauch [mailto:jared at]
>> Sent: Wednesday, May 19, 2010 1:29 PM
>> To: Jeff Harper
>> Cc: Deric Kwok; nanog at
>> 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 mask
> ip prefix-list NETZ description The networks we advertise via BGP
> ip prefix-list NETZ seq 10 permit
> ip prefix-list NETZ seq 1000 deny le 32

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