Stopping open proxies and open relays

Mon Feb 9 11:58:13 UTC 2004

----- Original Message -----
From: "Adi Linden" <adil at adis.on.ca>
To: <nanog at merit.edu>
Sent: Saturday, February 07, 2004 3:43 PM
Subject: Stopping open proxies and open relays

>
> I am looking for ideas to stop the spam created by compromised Windows
> PC's. This is not about the various worms and viruses replicating but
> these boxes acting as open relays or open proxies.
>
> There are valid reasons not to run antivirus software, coupled with
> clueless users, this results in machines that SPAM again just a few hours
> after having been cleaned.
>

Optus in Australia have taken the line of blocking port 25 to anything at
all excepting contact with their own servers. Seems to work. Some pissed off
customers with their own smtp progs etc but my guess is that this would fit
your bill.

Greg.