North American Network Operators Group

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Re: smurf's attack...

  • From: Jordyn A. Buchanan
  • Date: Fri Sep 05 16:19:31 1997

At 2:45 PM -0500 9/5/97, Jon Green wrote:
>On Fri, 5 Sep 1997 15:24:58 -0400, [email protected] writes:
>>We're also using the following extended access list (along with
>>anti-spoofing filters) to prevent smurf attacks from originating from our
>>access-list XXX deny ip any
>Folks, this is a bad idea.  There are lots of completely valid IP
>addresses out there that end in .255.  True, most of them that
>end in .255 ARE broadcast addresses, but if people implement this
>kind of filtering on a large scale, it really breaks classless IP.

Eep, this is true.  (Stupid me).

Haven't had any complaints yet from users unable to access anything yet,
but so much for making the 'Net slightly safer from this crap.


|Jordyn A. Buchanan                    mailto:[email protected] |
|Bestweb Corporation             |
|Senior System Administrator                     +1.914.271.4500 |