nanog mailing list archives
Re: Stealth Blocking
From: Valdis.Kletnieks () vt edu
Date: Thu, 24 May 2001 14:02:30 -0400
On Thu, 24 May 2001 09:46:19 PDT, "Eric A. Hall" said:
TCP rate-limiting on outbound traffic to *:25 would also be extremely effective, particularly on unclassified customer traffic, and without the heavy-handed nature of denying all dial-up traffic. Rate-limiting doesn't interfere with low-volume legitimate mail, but it really cramps spam.
I've seen a number of opinions that it doesn't do squat to cramp spam. Remember that the spammer is handing the "open" relay one piece of mail with zillions of RCPT TO:s - rate limiting the outbound just means that the zillions of recipients sit in *your* queue that much longer. Also, I have heard from multiple sources that the spammers are well clued enough to utilize multiple relays in parallel - if you rate limit to 1/N of bandwidth, they just use N relays at the same time. The problem is that you shoot YOURSELF in the foot by DOS'ing yourself by the time you get N cranked high enough to do any serious damage to the spammer.... -- Valdis Kletnieks Operating Systems Analyst Virginia Tech
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Current thread:
- RE: Stealth Blocking, (continued)
- RE: Stealth Blocking David Schwartz (May 23)
- Re: Stealth Blocking Shawn McMahon (May 24)
- RE: Stealth Blocking Roeland Meyer (May 23)
- Re: Stealth Blocking Christopher B. Zydel (May 23)
- RE: Stealth Blocking Roeland Meyer (May 23)
- RE: Stealth Blocking David Schwartz (May 23)
- Re: Stealth Blocking Richard A. Steenbergen (May 23)
- RE: Stealth Blocking Roeland Meyer (May 23)
- Re: Stealth Blocking Dave Rand (May 24)
- Re: Stealth Blocking Eric A. Hall (May 24)
- Re: Stealth Blocking Valdis . Kletnieks (May 24)
- Re: Stealth Blocking Eric A. Hall (May 24)
- Re: Stealth Blocking Shawn McMahon (May 24)
- Re: Stealth Blocking Steve Sobol (May 24)
- Re: Stealth Blocking Shawn McMahon (May 24)
- Re: Stealth Blocking Eric A. Hall (May 24)
- RE: Stealth Blocking Mike Batchelor (May 25)
- Re: Stealth Blocking Jason Slagle (May 24)
- Re: Stealth Blocking Mitch Halmu (May 24)