SMTP Port Blocking: Success or Failure?

Mon Feb 28 21:27:16 UTC 2005

How effective is rate limiting - can anyone from Comcast reaply to me
offlist, I would be very intersted in results ...

PR

-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu]On Behalf Of
John Levine
Sent: Sunday, February 27, 2005 11:20 AM
To: nanog at nanog.org
Cc: kfroyn at gnr.com
Subject: Re: SMTP Port Blocking: Success or Failure?

>What about rate limiting SMTP traffic rather than blocking it? That
>could allow legitimate use for most private customers, while
>preventing bulk traffic.

Comcast has been doing something like that, looking for spikes of SMTP
connects and blocking when they see them, done at the IP level.  I
can't say that I'm overly impressed with how well it's working, but
it's better than nothing.

Regards,
John Levine, johnl at iecc.com, Primary Perpetrator of "The Internet for
Dummies",
Information Superhighwayman wanna-be, http://www.johnlevine.com, Mayor
"I dropped the toothpaste", said Tom, crestfallenly.