Subnet Size for BGP peers.

Mikael Abrahamsson swmike at
Thu Jul 30 04:28:26 UTC 2009

On Thu, 30 Jul 2009, Benjamin Billon wrote:

> Who knows any other good way to lose IP addresses?

I know how to not lose them:

int lo30
ip address

int gi2.10
encap dot1q 10
desc cust 1
ip address unnumbered lo30

int gi2.11
encap dot1q 11
desc cust 2
ip address unnumbered lo30

ip route gi2.10
ip route gi2.11

etc. Now you can have one customer per vlan but still have them share the 
same IP subnet. This works with vlan interfaces as well.

I don't remember if you have to do local-proxy-arp or not, but if you're 
running bgp you could always do next-hop-self to be sure it hops via the 

Mikael Abrahamsson    email: swmike at

More information about the NANOG mailing list