Date: Tue, 19 Jul 2005 11:14:11 -0400 From: Hornet <hornetmadness@gmail.com> To: freebsd-questions@freebsd.org Cc: vladone <vladone@spaingsm.com> Subject: Re: DoS prevention .Sysctl parameters to prevent this? Message-ID: <f42935a605071908147f68a763@mail.gmail.com> In-Reply-To: <44ll42j2ey.fsf@be-well.ilk.org> References: <1188328635.20050718140416@spaingsm.com> <44ll42j2ey.fsf@be-well.ilk.org>
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On 19 Jul 2005 10:28:21 -0400, Lowell Gilbert <freebsd-questions-local@be-well.ilk.org> wrote: > vladone <vladone@spaingsm.com> writes: >=20 > > Recently i have in gateway freebsd that go down due to an DoS attack. > > I dont know exactly what is (i dont have experience), but is useful if = someone, with more > > wiyh more experience, can give some parameters for sysctl to prevent > > Dos an flood problem. > > Or perhaps with ipfw rules. > > Any help will be apreciated! >=20 > The question is too general. Every resource that is consumed by > incoming traffic is potentially subject to a denial-of-service > attack. =20 =20 > Furthermore, most denial-of-service attacks are actually > using up your incoming bandwidth, so there isn't much you can do on > your machine after those packets have already traversed your incoming > link. You hit the nail on the head. Really the best this you can do, is have tight firewall, netflow samples of your in/out data, and some cool scriptage to figure out if something is happening (and I'm talking about more the just some pretty graphs). Then call your ISP to block the hosts. Now if this is a DDoS and it is from a well built network, pretty much you will have to have the ISP null your host or network until it subsides. >=20 > See the manual for security(7), and see if that gives you a good start. >=20 > -- > Lowell Gilbert, embedded/networking software engineer, Boston area > http://be-well.ilk.org/~lowell/ > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.o= rg" >
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