Re: Packets from net 10 (no, not the lyrics)

["Todd R. Stroup" <tstroup () fibernet net>]

On Tue, 23 Sep 1997, John A. Tamplin wrote:

> Maybe I am missing something, but we use an inbound access list on all
> external links that eliminates IP address spoofing, as well as some basic
> security issues (blocking NFS, r* commands, etc just in case some machine
> inside is misconfigured).  If you have an inbound access list that filters
> based on the source address already, why would you not add the private 
> addresses to that?

This is sort of a different issue.. you are filtering IP not routes. If
you peer with someone that is sending you 10/8 even though you have it
filtered on the inbound of your interface (which is good for CPU) you will
still have a route injected into your route tables which could be 
bad.  Why not destroy the bad routes before they get to your routing 
table? 

Todd R. Stroup
Fiber Network Solutions, Inc.

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