nanog mailing list archives
Re: router syn/syn-ack/ack alarming...
From: Vern Paxson <vern () ee lbl gov>
Date: Wed, 18 Sep 96 11:12:05 PDT
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. The bookkeeping to tell a true syn-ack or ack-syn-ack from a bogus one entails keeping around connection state, and suddenly the cheap ratio gets expensive. Vern - - - - - - - - - - - - - - - - -
Current thread:
- Re: router syn/syn-ack/ack alarming..., (continued)
- Re: router syn/syn-ack/ack alarming... Alex.Bligh (Sep 17)
- Re: router syn/syn-ack/ack alarming... Mr. Jeremy Hall (Sep 17)
- Re: router syn/syn-ack/ack alarming... Perry E. Metzger (Sep 17)
- Re: router syn/syn-ack/ack alarming... Jeff Young (Sep 17)
- Re: router syn/syn-ack/ack alarming... Vadim Antonov (Sep 17)
- Re: router syn/syn-ack/ack alarming... Paul Ferguson (Sep 18)
- Re: router syn/syn-ack/ack alarming... Guy T Almes (Sep 18)
- Re: router syn/syn-ack/ack alarming... Michael Dillon (Sep 18)
- Re: router syn/syn-ack/ack alarming... Guy T Almes (Sep 18)
- Re: router syn/syn-ack/ack alarming... Justin W. Newton (Sep 18)
- Re: router syn/syn-ack/ack alarming... Vern Paxson (Sep 18)
- Re: router syn/syn-ack/ack alarming... Michael Dillon (Sep 18)
- Re: router syn/syn-ack/ack alarming... Larry J. Plato (Sep 18)
- Re: router syn/syn-ack/ack alarming... George Herbert (Sep 18)
- Re: router syn/syn-ack/ack alarming... Mark A. Fullmer (Sep 18)
- Re: router syn/syn-ack/ack alarming... Michael Dillon (Sep 18)
- Re: router syn/syn-ack/ack alarming... Michael Dillon (Sep 18)
- Re: router syn/syn-ack/ack alarming... Michael Dillon (Sep 18)
- Re: router syn/syn-ack/ack alarming... Curtis Villamizar (Sep 18)