I think the size and the fact that his ISP could not filter this
indicates that the problem cannot be solved locally. You can do all
the blocking on your end you want, but they can (and did) still
saturate links ahead of you.

Your ISP (or even their uplink, I'm guessing your ISP was also pretty
affected by this attack if they couldn't filter it) needs to step up
to bat in times like this.

-Patrick

2008/5/28 Ivailo Tanusheff <[EMAIL PROTECTED]>:
>
> Hi,
>
> What I wanted to say was to use pf, not ipf. You may use something like
> this:
>
> table <sshspammer> persist
> block log quick from <sshspammer>
>
> # sshspammer
> # more than 6 ssh attempts in 15 seconds will be blocked ;)
> pass in quick on $ext_if proto tcp to ($ext_if) port ssh keep state
> (max-src-conn 10, max-src-conn-rate 6/15, overload <sshspammer> flush
> global)
>
> which I use for ssh flood protection or brute force attacks. You have to
> change the syntax to use it for DNS.
> Hope this will help you.
>
> Regards,
>
> Ivailo Tanusheff
>
>
>
>
> Kalpin Erlangga Silaen <[EMAIL PROTECTED]>
> Sent by: [EMAIL PROTECTED]
> 28.05.2008 11:34
>
> To
> Ivailo Tanusheff <[EMAIL PROTECTED]>
> cc
> "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org>,
> [EMAIL PROTECTED]
> Subject
> Re: Survive from DDoS
>
>
>
>
>
>
> Dear Ivailo,
>
> thank you for your response. I am using ipfw to limit all packets for
> all open port in my server. But the packet size was 600 Mbps which could
> not filtered by our ISP.
>
> Ivailo Tanusheff wrote:
> > Hi,
> >
> > you may use ipf to drop packets from the attacking host I suppose. Or
> even
> > limit the packets to the specified port.
> >
> > Regards,
> >
> > Ivailo Tanusheff
> >
> >
> >
> >
> > Kalpin Erlangga Silaen <[EMAIL PROTECTED]>
> > Sent by: [EMAIL PROTECTED]
> > 28.05.2008 05:01
> >
> > To
> > "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org>
> > cc
> >
> > Subject
> > Survive from DDoS
> >
> >
> >
> >
> >
> >
> > Dear all,
> >
> > yesterday, our shell server was attack and server immeditiately reboot.
> > I checked logs, it likes UDP flood with destination port 53. Is there
> > any way how to survive from this kind attack? Also, is there any
> > url/resources to improve our shell server?
> >
> > Thank you
> >
> >
> > Kalpin Erlangga Silaen
> >
> >
> > _______________________________________________
> > freebsd-questions@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> > To unsubscribe, send any mail to
> "[EMAIL PROTECTED]"
> >
>
> _______________________________________________
> freebsd-questions@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to
> "[EMAIL PROTECTED]"
>
> _______________________________________________
> freebsd-questions@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to "[EMAIL PROTECTED]"
_______________________________________________
freebsd-questions@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to "[EMAIL PROTECTED]"

Reply via email to