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Re: How do you stop outgoing spam?

  • From: Eliot Lear
  • Date: Mon Sep 09 21:20:28 2002 
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