Followup on ping flood

From: Talley, Brooks (brooksat_private)
Date: Sat May 05 2001 - 14:18:34 PDT

  • Next message: Keith Owens: "Re: DNS ports and scans"

    Thanks to everyone who took the time to respond, publicly or privately.
    
    We're still experiencing 18Mbps (not mbps, as one smart alleck noted
    that 18 milli-bits wasn't very much at all) of incoming traffic.  It's
    really not a big deal, as our pipe and router are fine with it.  It's
    more just annoying, and disruptive of our stats and accounting.
    
    Our ISP (AboveNet) has blocked several single addresses but it loath to
    block an entire /16.  I don't really know why, but then again, I don't
    really care.  Their abuse department is attempting to contact the
    upstreams on the way back to the offending subnet, and in general
    AboveNet has been really very responsive and helpful.
    
    I appreciate the sentiment of the gentleman who cautioned against
    jumping to the conclusion that the perpetrator is from China, in light
    of recent political developments.  Still, since the site under attack is
    www.whitehouse.org, and because in addition to the ping flood, we're
    seeing more or less constant port scans originating from netblocks
    registered to China, I think Occam's razor suggests that that's the most
    likely interpretation.
    
    I've forwarded on Andriy Bilous's interesting suggestion of asking our
    upstream to implement CAR to rate limit ICMP.  On that note, we require
    some ICMP into our network for other purposes, so we can't just block it
    altogether upstream (and AboveNet is very resistant to implementing
    packet filtering rules on their big routers, and I don't blame them).
    
    This list is (and should be) technical rather than political, but this
    situation has made be think a bit about how to react to international
    net abuse, particularly with regards to the current political situation
    vis-a-vis the US and China.  I've come to the conclusion that my first
    instinct -- to simply block all traffic coming from China -- is actually
    a bad idea all the way around.  The alternative I've come up with is
    much more satisfying; I'm serving various human rights and international
    news pages to my Chinese clients.
    
    Anyways, I appreciate all the feedback.  I do suspect that the machines
    attacking us were themselves compromised, as the traffic has fallen from
    27Mbps to 18Mbps in a curve consistant with admins finding and shutting
    off machines.  Plus, I don't think anyone wants to pay for that kind of
    bandwidth for ping floods.
    
    Thanks everyone
    -Brooks
    



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