how to protect name servers against cache corruption

Jon Lewis jlewis at
Fri Aug 1 03:47:24 UTC 1997

On Wed, 30 Jul 1997, Thomas H. Ptacek wrote:

> I suppose the operations context to this is, "hey, you realize DNS is
> COMPLETELY BROKEN? What are your plans for dealing with the possibility
> of someone posting exploits?" Do we simply stop using DNS?

The same could be said of IP.  If you forge packets and ICMP or UDP attack
someone, as long as your packets cross a busy enough NAP (say one of the
MAE's) you can do it with impunity and effectively knock entire ISP's off
the internet.

"And how do I configure my router for that?"  Use access-lists to prevent
your networks from accepting spoofed packets from your customers, or
insist that they use such filters on their routers. 

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