nanog mailing list archives

Re: Automatic shutdown of infected network connections


From: Jonathan Crockett <jcrockett () midco net>
Date: Tue, 2 Sep 2003 09:59:51 -0500


On Fri, Aug 29, 2003 at 09:44:11PM -0400, Sean Donelan wrote:

Some universities such as Vanderbilt University are automatically
shutting down network ports when they detected signature worm traffic.
Almost 25% of the students' computers were detected as infected when they
connected to the university network.

http://www.vanderbilthustler.com/vnews/display.v/ART/2003/08/29/3f4eb4b3537e0


How many ISPs disconnect infected computers from the network?  Do you
leave them connected because they are paying customers, and how else
could they download the patch from microsoft?

I work for a cable modem provider.  What we came up with is a modem config
that allows http, pop, and smtp while cutting the allowed bandwidth to 56k
upstream and 56k downstrem.  This way they can still get the needed updates,
but are not able to blast our network.  Secondary effect is that customer
will call in an complain about slow speeds, then our techs can tell them why,
they are slow and inform them how to fix the problem.

-- 
Jonathan Crockett
Network Engineer
Midcontinent Communications


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