North American Network Operators Group
Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: ideas for half-open sync flood fixs

  • From: Brian Murrell
  • Date: Fri Sep 20 13:18:04 1996 
from the quill of peter@telescan.com (Peter Cole) on scroll
<199609201650.MAA10156@merit.edu>
> fix 1.  Doesn't the network respond with ICMP message to the attacked
> host 
> telling it that the nonexistent host is unreachable.  The attacked host
> could 
> close a half open socket if it received a ICMP message with the
> corresponding 
> host address and socket port data.

Ideally.  A lot of firewalls silently drop packets which don't get past the
security policy to make port scanning take much longer than it would if
ICMP's were sent back.  No resets, no ICMP unreachable.

b.


--
Brian J. Murrell                                        Brian_Murrell@bctel.net
BCTel Advanced Communications                                   brian@ilinx.com
Vancouver, B.C.                                                brian@wimsey.com
604 454 5279
- - - - - - - - - - - - - - - - -