[51899] in North American Network Operators' Group
Re: How do you stop outgoing spam?
daemon@ATHENA.MIT.EDU (Eliot Lear)
Mon Sep 9 21:16:42 2002
Date: Mon, 09 Sep 2002 18:15:12 -0700
From: Eliot Lear <lear@cisco.com>
To: nanog@merit.edu
Cc: Paul Vixie <vixie@vix.com>, Fred Baker <fred@cisco.com>
Errors-To: owner-nanog-outgoing@merit.edu
Rafi Sadowsky wrote:
> Maybe I'm missing something obvious but do how you get rate-limiting per
> TCP *flow* with Cisco IOS ?
There is something called flow-based RED (FRED) but it consumes a whole
lot of memory because you have to keep track of lots more state. I
don't know about that code. At the least what you can do is use the
rate-limit command and rate limit *all* outbound TCP/80 traffic (or for
that matter all access-list captured traffic). Now, doing so will make
any but the most trivial outbound TCP/80 absolutely painful, and will
cause tail drop. See Cathy Wittbrodt's work in this space, which was
presented at NANOG some time ago.
Note, I'm not saying you should *do* this. It may be going a bit too
far for anti-spam.
Eliot
