nanog mailing list archives

Re: New and interesting network abuse.


From: Suresh Ramasubramanian <ops.lists () gmail com>
Date: Tue, 11 Jan 2005 13:12:40 +0530


Thread that I just started yesterday about port 25 blocking and if
more ISPs werent doing this bidirectionally.

Which is what your local ISP, and other ISPs that have dialup pools, must do.

--srs

On Tue, 11 Jan 2005 01:33:00 -0600, Ejay Hire <ejay.hire () isdn net> wrote:

My apologies if this strays off topic, but I wanted to share my recent
experience.

We had a collocation customer come in and request a t1 of pots lines for
their servers, then complaints that their "security" software wasn't
working because of our RPF checks.  As it turns out they were dialing up
to a local isp, and sending bulk email using our bandwidth, but the
dial-up's ip.... And receiving the TCP ack on the dial up.


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