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Bugtraq archives for 2nd quarter (Apr-Jun) 1994: Re: ICMP filtering?

Re: ICMP filtering?

Carl Corey (ccdesccdes.princeton.nj.us)
Thu, 28 Apr 1994 03:33:58 -0500 

>In a previous message ccdesccdes.princeton.nj.us wrote
>> I know we are getting a cisco router, and I have a question for anyone -
>> what is the latest version of the router software I need to run to keep
>> fake ICMP packets from reaching my hosts?  I believe that this was a
>> somewhat recent upgrade by cisco, thus the presence of nuke.c or whatever
>> being used to annoy people.  
>
>Is this true?  If so, I'd be interested to know how this is implemented
>and also what software revision is required.  We use quite a few routers
>here, some Cisco, some not.  I don't see how one could filter 'fake'
>icmp destination unreachable messages without actually filtering all
>real ones as well.

I believe that a majority of the packets "nuking" connections out there are
not perfect fakes; they are distinguishable from the real thing.