nanog mailing list archives
Re: Time to check the rate limits on your mail servers
From: Jørgen Hovland <jorgen () hovland cx>
Date: Thu, 3 Feb 2005 15:46:32 -0000
----- Original Message ----- From: "Gadi Evron" <ge () linuxbox org>
Allow me to elaborate; and forget about this article, why limited ourselves?Once big ISP's started blocking port 25/outbound for dynamic ranges, and it finally begun hitting the news, we once again caused the spammers to under-go evolution.In this particular case, they figured they'd have to find better ways to send spam out, because eventually, they will be out of working toys.
HelloI am a bit concerned that blocking any port at all preventing abuse of the affected service will make the abusers go through other services instead. Port 139/445 is already blocked by several isps due to excessive abuse or I believe they call it 'a security measurement'. Even port 23 has been blocked (inbound and outbound) by atleast 1 large isp I am aware of. When that mssql worm was lurking around isps were also blocking that port. I hope I'm not the only one seeing a pattern here. Really, blocking ports makes no sense to me in the long run. You are destroying the service, and even if you block all ports there are several ways to spam anyway. You would probably reply now saying that "yeah but you get rid of 99% of the spammers that way". That is only partly true. As time goes on all spammers will adopt to your isps new "security policy" and if you still don't see the pattern I am talking about now there is nothing more I can say. I don't have the solution to all of this, but I sure know how to see what is not the solution. Teach people how to write "Hello world" better perhaps.
Joergen Hovland Joergen Hovland ENK
Current thread:
- Re: Time to check the rate limits on your mail servers, (continued)
- Re: Time to check the rate limits on your mail servers up (Feb 03)
- Re: Time to check the rate limits on your mail servers John Levine (Feb 05)
- Re: Time to check the rate limits on your mail servers Rich Kulawiec (Feb 03)
- Re: Time to check the rate limits on your mail servers Gadi Evron (Feb 03)
- Re: Time to check the rate limits on your mail servers Raymond Dijkxhoorn (Feb 03)
- Re: Time to check the rate limits on your mail servers Gadi Evron (Feb 03)
- Re: Time to check the rate limits on your mail servers Raymond Dijkxhoorn (Feb 03)
- Re: Time to check the rate limits on your mail servers Gadi Evron (Feb 03)
- Re: Time to check the rate limits on your mail servers Michael . Dillon (Feb 03)
- Re: Time to check the rate limits on your mail servers Scott Weeks (Feb 03)
- Re: Time to check the rate limits on your mail servers Raymond Dijkxhoorn (Feb 03)
- Re: Time to check the rate limits on your mail servers Jørgen Hovland (Feb 03)
- Re: Time to check the rate limits on your mail servers Gadi Evron (Feb 03)
- Re: Time to check the rate limits on your mail servers Jason Frisvold (Feb 03)
- Re: Time to check the rate limits on your mail servers Valdis . Kletnieks (Feb 03)
- Re: Time to check the rate limits on your mail servers Jason Frisvold (Feb 03)
- Re: Time to check the rate limits on your mail servers Todd Vierling (Feb 03)
- Re: Time to check the rate limits on your mail servers Nils Ketelsen (Feb 03)
- Re: Time to check the rate limits on your mail servers Petri Helenius (Feb 03)
- Re: Time to check the rate limits on your mail servers Rich Kulawiec (Feb 03)
- Re: Time to check the rate limits on your mail servers Andy Johnson (Feb 03)
- Re: Time to check the rate limits on your mail servers Jørgen Hovland (Feb 03)