nanog mailing list archives

Re: Is there a line of defense against Distributed Reflective attacks?


From: "Christopher L. Morrow" <chris () UU NET>
Date: Fri, 17 Jan 2003 03:59:21 +0000 (GMT)



On Thu, 16 Jan 2003, hc wrote:


This type of DRDOS (Distributed Reflective Denial of Service Attack) is
well commonly-known to both network operators, and as well as many
script-kiddies.

By forging the source IP address of the attack to the victim's IP, and
attacking internet backbone routers, this creates an immediate,
devastating, yet very effective attack. Backbone routers, seeing this as
legitimate packets simply reply back to the victim.

I guess the question is, what are the internet backbones doing these
days to evade the outcome of reflected DoS attacks? Are they simply
going to let their routers be the middleman to kick off innocent hosts?

SYN cookies and various other methods to control DoS attacks are only

Because syn cookies are available on routing gear??? Either way syn
cookies are not going to keep the device from sending a 'syn-ack' to the
'originating host'.

used by smart ISP's.. And considering most ISP's do not even care about
egress filters, I don't believe any of these methods will work for quite
some time to come.

-hc


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