nanog mailing list archives

Re: BCP38 making it work, solving problems


From: JP Velders <jpv () veldersjes net>
Date: Tue, 19 Oct 2004 19:14:32 +0200 (CEST)



Date: Tue, 19 Oct 2004 09:21:46 -0700
From: Randy Bush <randy () psg com>
Subject: Re: BCP38 making it work, solving problems

For example, how many ISPs use TCP MD5 to limit the possibility of a
BGP/TCP connection getting hijacked or disrupted by a ddos attack?

i hope none use it for the latter, as it will not help.  more and
more use it for the former.  why?  becuase they perceived the need
to solve an immediate problem, a weakness in a vendor's code.

Uhm, you might need to run that by me again...

Hijacking the connection is in a completely different class as someone
bombarding you with a bunch of forged BGP packets to close down a
session. Without that MD5 checksum you are quite vulnerable to that. I
haven't seen a vendor come up with a solution to that, because the
problem is on a much more vendor-neutral level...

Regards,
JP Velders

PS: ofcourse that MD5 option also causes problems for peerings to come
    back "up" again if you have to reboot/reload *without* properly
    closing them... :( Hey, pro's and con's are part of the job ;)


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