Re: Blackholing traffic by ASN

From: Christopher Morrow (no email)
Date: Thu Jan 31 2008 - 00:21:57 EST

  • Next message: Warren Kumari: "Re: potential hazards of Protect-America act"

    On Jan 30, 2008 3:54 PM, Deepak Jain <> wrote:
    >
    >
    > This is prior art. (Assuming your hardware has a hardware blackhole (or
    > you have a little router sitting on the end of a circuit)) you adjust
    > your route-map that would deny the entry to set a community or next-hop
    > pointing to your blackhole location.
    >
    > Nowadays, most equipment can blackhole internally (to null0 say) at full
    > speed, so it isn't an issue. Just set your next hop to a good null0
    > style location on route import and you are done for traffic destined to
    > those locations.
    >

    ...do uRPF-loose-mode and you kill FROM these locations as well...

    > For inbound traffic from those locations you would need to do policy
    > routing (because you are looking up on source). If you are trying to

    (uRPF loose-mode)

    > block SPAM or anything TCP related, you only need to block 1 direction
    > to end the conversation.
    >

    be cautious of 'synflooding' your internal hosts with this though...
    Null0 doesn't generate unreachables at packet-rate, but at a lower
    (1:1000 I believe on cisco by default) rate.

    > Sounds harsh, but hey, its your network.
    >

    wee! and for some extra fun, just append the bad-guy's ASN to your
    route announcements, force bgp loop-detection to kill the traffic on
    their end (presuming they don't default-route as well)


  • Next message: Warren Kumari: "Re: potential hazards of Protect-America act"





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