North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: router syn/syn-ack/ack alarming...
On Wed, 18 Sep 1996, Vern Paxson wrote: > > have something in their logs like SYN/ACK RATIO 33:1 POSSIBLE HACKER > > ATTACK which will make them sit up and take notice. > > I don't see how in reality to make the syn/syn-ack/ack ratio work soundly. > It seems too easy for the cracker to synthesize bogus syn-ack's or ack's to > manipulate the ratio however they please. Wouldn't the ratio be calculated from outgoing SYN's and incoming ACK's? I can see that a sophisticated attacker could have a machine on another network sending incoming ACK's to balance the outgoing SYN's but I suspect this would be an extremely small percentage of attacks. Michael Dillon - ISP & Internet Consulting Memra Software Inc. - Fax: +1-604-546-3049 http://www.memra.com - E-mail: [email protected] - - - - - - - - - - - - - - - - -
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