I have, for quite some time, had trouble with my BIND installation falsely claiming that certain domains don't exist. It tends to be pretty consistent about them - anything under yahoo.com can be counted on to display this, for instance.
The symptom, which is primarily noticable for outgoing email (handled by exim) and web browsing (netscape or mozilla), is that the first attempt to resolve the domain gets a 'not found' response, but retrying immediately afterward works fine. The domain then works properly for a while (presumably until the information on it gets dropped from BIND's cache), then it gives the spurious 'not found' again. This is presumably a timeout issue, but I haven't been able to verify that theory. For web browsing, it's an annoyance, but not a big deal - just resubmit the request and it works the second time. In mail, however, it's more significant... It started out with just getting 'non-routable mail domain' bounces and resending the message, but now I'm running a mailing list with a couple subscribers from UK domains that display this problem and Mailman eats the bounces, so there's no way to even detect when it happens until someone looks at the list archive and notices that there are archived messages which he never received. In my attempts to resolve this problem, I've updated my root hints and double-checked that I'm set to use my ISP's name servers as forwarders and that they work properly. (Interestingly enough, testing them again just before sending this message, both of the ISP nameservers resolved mail.yahoo.com instantly, but mine took several seconds to do so. Trying it again after a BIND restart, the first attempt came back with "can't find mail.yahoo.com: Non-existent host/domain" after 15 seconds on the first try, found the address after 5 seconds on the second try, and responded instantly on the third. This is repeatable.) What do I need to do to my configuration, whether of BIND or of exim, to make mail delivery bit more reliable? I would, ideally, like to fix this in BIND, of course, but at this point I would settle for a configuration setting to tell exim to always try delivery twice, even if the first attempt gets a 'Non-existent host/domain' error. -- The freedoms that we enjoy presently are the most important victories of the White Hats over the past several millennia, and it is vitally important that we don't give them up now, only because we are frightened. - Eolake Stobblehouse (http://stobblehouse.com/text/battle.html) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
