nanog mailing list archives
RE: SMTP relaying policies for Commercial ISP customers...?
From: Daniel Reed <n () ml org>
Date: Fri, 13 Feb 2004 18:06:43 -0500 (EST)
On 2004-02-13T15:30-0600, Ejay Hire wrote: ) You could use AOL's tactic and transparent proxy all ) outbound port 25 traffic. Then it'd be a relatively simple ) matter to add mr. spammer's ip to a hosts.deny. If you were You may also need to filter inbound packets with a source port of 25, or any other ports you capture. As I believe has been mentioned here before, some spammers may use a dialup account just for its IP address, collecting return packets on the dialup interface but sending the actual content through some higher-bandwidth, unfiltered pipe. Filtering what goes out over the dialup account would be largely ineffective in this case, as nothing actually needs to be sent through that interface for the transmissions to succeed. -- Daniel Reed <n () ml org> http://naim-users.org/nmlorg/ http://naim.n.ml.org/ "True nobility lies not in being superior to another man, but in being superior to one's previous self."
Current thread:
- Re: SMTP relaying policies for Commercial ISP customers...?, (continued)
- Re: SMTP relaying policies for Commercial ISP customers...? Steven Champeon (Feb 13)
- Cisco Secure ACS Solution Engine-a 1-RU Mr. James W. Laferriere (Feb 13)
- Re: SMTP relaying policies for Commercial ISP customers...? Steven Champeon (Feb 13)
- RE: SMTP relaying policies for Commercial ISP customers...? Dan Ellis (Feb 13)
- RE: SMTP relaying policies for Commercial ISP customers...? Andy Dills (Feb 13)
- Re: SMTP relaying policies for Commercial ISP customers...? Leo Vegoda (Feb 13)
- Re: SMTP relaying policies for Commercial ISP customers...? Petri Helenius (Feb 13)
- Re: SMTP relaying policies for Commercial ISP customers...? jlewis (Feb 13)
- Re: SMTP relaying policies for Commercial ISP customers...? Joseph Noonan (Feb 13)
- Re: SMTP relaying policies for Commercial ISP customers...? Andy Dills (Feb 13)
- RE: SMTP relaying policies for Commercial ISP customers...? Andy Dills (Feb 13)
- RE: SMTP relaying policies for Commercial ISP customers...? Ejay Hire (Feb 13)
- RE: SMTP relaying policies for Commercial ISP customers...? Daniel Reed (Feb 13)