nanog mailing list archives

Re: Anti-spam System Idea


From: Sean Donelan <sean () donelan com>
Date: Sun, 15 Feb 2004 17:46:05 -0500 (EST)


On Sun, 15 Feb 2004 Valdis.Kletnieks () vt edu wrote:
DialUp Lists (DUL) dns block lists permits you to ignore e-mail from
many dynamic IP addresses. You can configure your mail server to do this
today without waiting for ISPs to do anything.

If we advertise the DHCP pools for AS1312 in a DUL, we solve the problem for
those sites that use the DUL we list them in.

What if I told you about a method to identify the type of connection for
every IP address in our DNS?  You don't need to rely on third-party DUL
lists.

Blocking is a binary decision.  Instead if you have better information
about the connection source, you can make different decisions how to
handle the message.

If we block outbound port 25 SYN packets from origin addresses in the DHCP
address blocks, we solve the problem for everybody.

Including the people who don't want you to solve it for them.

People want to use outbound port 25 from dynamic address blocks.  Why
block it between people who want to use it just because some people
want to have open servers?

Block 119, you must use your ISPs NNTP server.
Block 6667, you must use your ISPs IRC server
Block 80, you must use your ISPs HTTP proxy.
Block N, you must use your ISPs whatever server.

Enterprises already do this, the equipment exists.  Why do we want ISPs
doing this?


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