Re: Filtering on RFC1918 cruft

[Sean Donelan <SEAN () SDG DRA COM>]

> deny   ip 198.32.146.0 0.0.0.255 255.255.255.0 0.0.0.255 (543 matches)
> deny   ip 198.32.176.0 0.0.0.255 255.255.255.0 0.0.0.255 (10 matches)
> deny   ip 192.157.69.0 0.0.0.255 255.255.255.0 0.0.0.255 (96 matches)
> deny   ip 198.32.128.0 0.0.0.255 255.255.255.0 0.0.0.255 (335 matches)
>
>  ya, ya, teh last four aren't rfc1918 but i filter them anyway (nap 
> dmz's) :)  lot's of people announcing them.  the first two are the 
> only rfc1918 nets i see announced on our nap routers.

I used to wonder about announcing them too.  I came up with reasons
on both sides, and in the end decided it didn't matter for real
traffic.  Real traffic isn't sourced or destined for the exchange
point networks.  On the other hand, the users most likely to send
traffic to or from an exchange point network are also the network
engineers configuring the announcements.  Announcing the networks
make network debugging (and other network hacking) a lot easier. 
-- 
Sean Donelan, Data Research Associates, Inc, St. Louis, MO
  Affiliation given for identification not representation
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