Date: Tue, 06 Apr 2004 22:12:34 -0400 From: David <ph1@cogeco.ca> To: freebsd-security@freebsd.org Subject: Re: SYN attacks (correction) Message-ID: <40736392.8060708@cogeco.ca> In-Reply-To: <402CF87001176A54@> (added by postmaster@iprimus.com.au) References: <402CF87001176A54@> (added by postmaster@iprimus.com.au)
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Mark Picone wrote: > you should add > net.inet.tcp.drop_synfin=1 to /etc/sysctl.conf so it gets piped into sysctl > on boot > or just run sysctl net.inet.tcp.drop_synfin=1 as root Unlikely the attacks will have both the SYN and FIN flags set. Perhaps verifying net.inet.tcp.syncookies is set to 1 and use ipfw+dummynet to rate limit incoming SYN packets. > > -----Original Message----- > From: owner-freebsd-security@freebsd.org > [mailto:owner-freebsd-security@freebsd.org] On Behalf Of Mark Picone > Sent: Wednesday, 7 April 2004 10:57 am > To: freebsd-security@freebsd.org > Subject: RE: SYN attacks > > You could try adding this to /etc/sysctl.conf > > sysctl net.inet.tcp.drop_synfin=1 > > -----Original Message----- > From: owner-freebsd-security@freebsd.org > [mailto:owner-freebsd-security@freebsd.org] On Behalf Of Spades > Sent: Wednesday, 7 April 2004 3:02 am > To: freebsd-questions@freebsd.org > Cc: freebsd-security@freebsd.org > Subject: SYN attacks > > Heya, > > FREEBSD 4.9-STABLE > > Is there anyway to block SYN attacks and prevent it from bring down my > server? > > Its been attacking for sometime. > _______________________________________________ > freebsd-security@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-security > To unsubscribe, send any mail to "freebsd-security-unsubscribe@freebsd.org" > > _______________________________________________ > freebsd-security@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-security > To unsubscribe, send any mail to "freebsd-security-unsubscribe@freebsd.org" > > _______________________________________________ > freebsd-security@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-security > To unsubscribe, send any mail to "freebsd-security-unsubscribe@freebsd.org" >
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