Re: improved synflood protection & detection

From: Oliver Friedrichs (oliverat_private)
Date: Wed May 06 1998 - 14:01:24 PDT

  • Next message: Gert Doering: "Re: improved synflood protection & detection"

    On Wed, 6 May 1998, VaX#n8 wrote:
    
    > Many if not all of the addresses in the above blocks are unused.
    > Affording ingress to TCP packets to which you cannot respond
    > seems pointless and a bit temerarious.
    > It may be worthwhile to generate list of all address blocks not
    > recently routed and construct a filter based on those.
    > It may also be useful to log these packets for auditing, so
    > you can detect if the status of a block changes.
    
    This really won't work.  It may have worked if every single IP address on
    every single registered network were in use and reachable 100% of the
    time.  I can pick any random registered network and find addresses on that
    network which aren't currently being used, or with hosts that aren't
    reachable (behind a firewall).
    
    - Oliver
    
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