nanog mailing list archives

Re[4]: SYN floods (was: does history repeat itself?)


From: pcalhoun () usr com (Pat Calhoun)
Date: Fri, 13 Sep 1996 15:59:31 -0500

     Curtis,
     
        As I stated in my previous e-mail, we could do this by adding this 
     to our release notes in our product, describing the problem and 
     advising against not taking measures. However, this would only apply 
     to our customers, which I would venture to say that most already do 
     understand the problem :).
     
        However, if there is anything that I can do to help, please let me 
     know since I take the threat of the "imminent death of the internet" 
     very seriously.
     
     
     Pat R. Calhoun                                e-mail: pcalhoun () usr com 
     Project Engineer - Lan Access R&D                phone: (847) 933-5181 
     US Robotics Access Corp.
     
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Subject: Re: Re[2]: SYN floods (was: does history repeat itself?) 
Author:  Curtis Villamizar <curtis () ans net> at Internet 
Date:    9/12/96 1:44 PM
     
     
     
In message <233128C0.3000 () usr com>, Pat Calhoun writes: 
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     Perry,
     
        This is actually quite simple to implement on Dial Access Routers, 
     and obviously this is the best place to add the filtering. 
     
     
     Pat R. Calhoun                                e-mail: pcalhoun () usr com 
     Project Engineer - Lan Access R&D                phone: (847) 933-5181 
     US Robotics Access Corp.
     
     
I agree with you completely -- sort of.  Only problem is there are 
thought to be some 3,000 dial access providers.  Many of them barely 
know what a TCP SYN is, let alone why they need to block ones with 
random source addresses and how.  Unless of course you are 
volunteering to explain it and help them.  Thanks in advance.  :-)
     
Curtis
     
     
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Subject: Re: SYN floods (was: does history repeat itself?) 
Author:  "Perry E. Metzger" <perry () piermont com> at Internet 
Date:    9/9/96 1:19 PM


     
Re: SYN floods
     
PANIX, a large public access provider in New York, was badly hit with 
SYN flood attacks from random source addresses over the last few 
days. It nearly wrecked them.
     
I think its time for the larger providers to start filtering packets 
coming from customers so that they only accept packets with the 
customer's network number on it. 
     
Yes, its a load on routers. Yes, its nasty for the mobile IP weenies. 
Unfortunately, the only known way to stop this. Many TCPs go belly up 
as soon as they get SYN flooded -- its a defect in the protocol 
design, and other than Karn style anti-clogging tokens ("cookies") 
being put into a TCP++ and mass implemented worldwide soon, the only 
reasonable way to stop this sort of terrorism is provider filtering. 
     
Perry
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To: nanog () merit edu
Subject: Re: SYN floods (was: does history repeat itself?) 
In-reply-to: Your message of "Mon, 09 Sep 1996 12:47:13 EDT." 
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Date: Mon, 09 Sep 1996 13:19:02 -0400
From: "Perry E. Metzger" <perry () piermont com> 
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