nanog mailing list archives
Re: question on ptr rr
From: Paul Vixie <vixie () vix com>
Date: 08 Feb 2004 20:29:17 +0000
sean () donelan com (Sean Donelan) writes:
A Google search turned up http://www.unixwiz.net/techtips/pacbell-rdns.html But wouldn't this defeat the very behavior you are depending on to block mail? If every network administrator had reverse DNS for every IP address, your check for systems lacking rDNS wouldn't work.
that's one check of many. the PTR has to match the HELO, which means all of the worms and spammers who forge @yahoo.com addresses and use YAHOO.COM as their HELO will continue to get hammered.
Or do we actually want a Fortune 1000 network. Direct communications are prohibited between most users. If you are not a Fortune 1000 network, you must forward your email through an approved provider which will check the mail for unauthorized content.
yes, actually, that's what we're headed for.
Suppose AOL, MNN, Yahoo, etc agree to accept mail from each other and not from other people. This is pretty much how the world worked from 1980-1990. CompuServe, MCIMail, The Source, Delphi, etc.
fine by me. the people i want to exchange mail with aren't AOL users anyway. -- Paul Vixie
Current thread:
- Re: question on ptr rr, (continued)
- Re: question on ptr rr Randy Bush (Feb 10)
- Message not available
- Re: question on ptr rr Suresh Ramasubramanian (Feb 10)
- Message not available
- Re: question on ptr rr Suresh Ramasubramanian (Feb 10)
- Re: question on ptr rr Randy Bush (Feb 07)
- Re: question on ptr rr Sean Donelan (Feb 07)
- Re: question on ptr rr Steven M. Bellovin (Feb 08)
- Re: question on ptr rr Paul Vixie (Feb 08)
- Re: question on ptr rr Sean Donelan (Feb 07)
- Re: question on ptr rr Paul Vixie (Feb 08)
- Re: question on ptr rr Andrew - Supernews (Feb 08)
- Re: question on ptr rr garrett.allen (Feb 08)
- Re: question on ptr rr Chris Adams (Feb 08)
- Re: question on ptr rr Andrew - Supernews (Feb 08)
- Re: question on ptr rr Niels Bakker (Feb 09)
- Re: question on ptr rr Robert E. Seastrom (Feb 09)
- Re: question on ptr rr Daniel Senie (Feb 09)