nanog mailing list archives

Re: WANTED: ISPs with DDoS defense solutions


From: "Jason Robertson" <jason () ifuture com>
Date: Tue, 05 Aug 2003 22:58:40 -0400


They have existed in the past it was how many an irc server was 
hacked..  It's just not easy to accomplish but there are many hacker 
tools to do this still available, some with better capabilities at this 
then others.

Also you could have 2 ip addresses on the same host different 
interfaces eg 10.0.0.2 and 10.0.0.3, and use 10.0.0.2 and spoof 
10.0.0.3 as the source, and since you can listen to both interfaces, 
you can determine if it arrived on the wrong interface.

jason

On 5 Aug 2003 at 21:31, Barney Wolff wrote:


On Wed, Aug 06, 2003 at 12:58:19AM +0000, Paul Vixie wrote:

could someone here who can write win32 apps, and someone else who can
write cocoa apps, please volunteer short executables that will try to
spoof a few packets through some well known server, and then report as
to whether the current computer/firewall/cablemodem/isp/core permitted
this or not?  isc would be happy to host the server component of this,
as long as source code for the executables is available under a bsd
style copyright, and the executables are released without any fee.

How would the spoofing program, or its user, be able to tell if
it was successful?  Unless I'm very confused, the definition of
spoofing is that the return packets aren't going to come back to you.

I can imagine a packet format where the real source address was in the
data, but with no authentication this would itself be subject to abuse.
You'd need a little protocol:

Volunteer                        Server
real-source-->server
                            <--back to real source with ip to fake, cookie
fake-source-->server with cookie
                            <--back to real source with result as a courtesy

Doing this from behind a NAT would be difficult.

-- 
Barney Wolff         http://www.databus.com/bwresume.pdf
I'm available by contract or FT, in the NYC metro area or via the 'Net.




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