On Tue, 27 Mar 2001 19:55:54 -0800, PB wrote: >Agreed. I was hoping this rare type of failure, no changes >to the system and the reverse lookup of 3 IPs stops working >might be 'known' to the list readers. The problem went away >March 23 at 21:19:07. That was a few hours after I posted >to the list after 3 days of struggling to find out why these >IP number would not reverse lookup. Other numbers in the >same class C IP range would lookup. What does dig say when you try to resolve those addresses? Try "dig -x ip-number +d2". (The +d2 turns on extra-verbose DNS debugging.) >Hmm, looking at the log the reverse failed again starting >March 26 at 11:26 for my 5 popper accounts. And on the same >day at 21:47 started working again. And is still working now. >Resolution is every 6 minutes the popper accounts are checked. > >The popper account 'kelly' continues to fail. >The popper account 'david' continues to be intermittent >but not at the same frequency as my 5 accounts. It's probably not related to the account, except in that the user using that account is always using a specific IP address to check his mail. Let us know the addresses that are failing. There's lots of misconfigured DNS servers out there, and it's good to let their admins know when they're screwed up. >As the problem appeared by itself and left by itself, it makes >me wonder how truly marvelous DNS is. The good thing about DNS is that it's distributed. No single point of failure. Otherwise *all* your accounts would fail. I was getting a resolver failure a couple of weeks ago and traced it to one of my users checking his mail from his DSL account at home in Novato, CA. I looked into the failure (with dig) and found his ISP was running an ancient (and hence vulnerable) version of BIND, and had no PTR records for his users. I let the hostmaster know about the problem. Hopefully he's fixing it. Ken mailto:[EMAIL PROTECTED] http://www.sewingwitch.com/ken/ [If answering a mailing list posting, please don't cc me your reply. I'll take my answer on the list.]
