[nsp] /30 over WAN links

Steve Lim limmer at execpc.com
Fri Feb 6 10:32:48 EST 2004

Hello all,

	It has been an age old policy at my company to place a /30 over the WAN 
links ever since who knows when, and I've never really questioned it. 
But now, we've merged with another company, and they do not follow such 
a policy at the Access Layer. In fact, they use a /29 (or shorter 
prefixes, if customer requires more IPs) over the WAN links, and  use 
the IPs not already used by the respective end interfaces for 
hosts/devices on the remote/customer end.

	I had assumed that most, if not all companies use /30s. So this came as 
a surprise. But more importantly, I can't come up with a good reason why 
we use /30s either.

My questions:

1. At the Access Layer, what are the benefits of using /30s, over 
subnets with shorter prefixes.

2. Are there administrative benefits to such a policy?

3. Are there routing or switching benefits to such a policy?

4. Is it a best practice policy?

Thank you for comments.

Steve Lim - Network Engineer (Michigan)
Corecomm -An ATX Communications Company
Support Bacteria, it's the only culture
everyone has in common. -limmer

More information about the cisco-nsp mailing list