RE: BSDI announcement about defense against syn-flooding attacks

[William Sommers <sommers () sfo com>]

On Thu, 3 Oct 96 16:35:13 PDT  Rob Liebschutz wrote:

> They've made a big announcement about it, but the code doesn't yet
> appear to be on their ftp site. The announcement does not describe
> what approach they took to solving the problem (presumably something
> more then their existing patch for the larg PCB hash table).  See
> http://www.bsdi.com/press/19961002.html for the full announcement.
>
> It scares me to think how much effort has gone into defense against
> this one denial of service attack when there are endless possibilities
> for other ones.

Actually, they released a number of patches all at once, including (quoting 
the notice just sent out by polk () bsdi com):

  The remainder of the patches (K210-021, K210-022, and U210-025)
  add support for IP source checking, and for reducing and/or
  eliminating problems associated with SYN attacks, IP fragment
  attacks, and some other denial of service/looped server attacks.

Unfortunately, these are available only for BSD/OS 2.1 -- nothing for prior 
releases.


 William Sommers
 San Francisco Online
 Televolve, Inc.
 sommers () sfo com


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