In message <4d4784c4.2020...@lcrcomputer.net>, Lyle Giese writes: > p...@mail.nsbeta.info wrote: > > Hi list, > > I can't setup a ptr RR for my mailserver's IP. > > Here the main ISPs who are owned by this garbage state take expensive > > price for setup a reverse record for a public IP. It's about 30 USD > > each month for each IP. > > But some MTAs does require the peer deliveragent has a PTR RR,like > > AOL's email systems. > > Is there a special RFC for this requirement? > > Regards. > > Mail Delivery System writes: > >> This is the mail system at host mail.nsbeta.info. > >> I'm sorry to have to inform you that your message could not > >> be delivered to one or more recipients. It's attached below. > >> For further assistance, please send mail to postmaster. > >> If you do so, please include this problem report. You can > >> delete your own text from the attached returned message. > >> The mail system > >> <dono...@beth.k12.pa.us>: host mx1.beth.k12.pa.us[209.96.96.11] said: > >> 450 4.7.1 > >> Client host rejected: cannot find your reverse hostname, [121.9.221.212] > >> (in reply to RCPT TO command) > I do not believe this to be fully covered in an RFC, but came about as > Best Practices as we fight SPAM. The best source for the Best Practices > for this is at http://postmaster.aol.com
And is also against RFC requirements. > Wonder through ALL of the pages that this area at AOL has to offer or > you will miss some important points, like that 12 hrs is considered the > min TTL for A and PTR records for mail servers. Less than 12 hrs TTL on > these records are considered by default indicators of dynamic IP addresses. You can't infer diddly squat from a TTL. There are plenty of reasons to want a low ttl other than it was assigned dynamically. * I'm going to renumber my whole network because I'm switchinhg ISP's so I've reduced my TTL's to 5 minutes to reduce the impact of the renumbering. * I have a warm spare in a different data center and as most client behave badly when one of the addresses is unreachable I only advertise one address. More stupid unrealistic hoops to jump through. Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
