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Re: SMURF amplifier block list
From: Hank Nussbacher <hank () ibm net il>
Date: Tue, 14 Apr 1998 13:42:57 +0200

At 03:31 AM 4/14/98 -0600, Forrest W. Christian wrote:
On Tue, 14 Apr 1998, Hank Nussbacher wrote:

All outgoing pkts to now should go to Null0.  I am sure
one can improve on the logic even more.

Exactly.  All OUTGOING packets.   Not Incoming. Not the smurf attack
packets which are swamping your downstream customer, which have a source
address from

My textual mistake - this snippet is to send pkts to dev/null for all pkts
*sourced* from  -Hank 

I will concede that shutting off connectivity to a site by a large enough
chunk of the net should get someone to fix stuff....  But part of the
advantage of the MAPS RBL BGP feed is that it helps to cut down spam
coming into your network.  A BGP feed TODAY won't block a ping
amplification attack aimed at your network or a downstream.  All it will
do is prevent your customers from using the ping amplification networks to
launch an attack.   And, if you have the appropriate anti-spoofing filters
in place, they shouldn't be able to attack anything other than the valid
source addresses you have in your outbound filter set.

- Forrest W. Christian (forrestc () imach com) 
iMach, Ltd., P.O. Box 5749, Helena, MT 59604      http://www.imach.com
Solutions for your high-tech problems.                  (406)-442-6648

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