On Mon, May 20, 2002 at 12:25:58PM -0500, Damon Anton Permezel wrote: > It is not a matter of a timeout.
Correct. The NS is actually reporting a transient error in response to AAAA queries. > The "A ?" come back fine. > `dig' and 'nslookup' both resolve the name -- there is no timeout. > `ping' works, for example. > > Because sendmail "correctly" (aka: anal-retentively) adheres to a > protocol, it flags this as an error, Not sure what's so anal-retentive. The NS tells sendmail(8) there is an error and sendmail(8) believes it. > and doesn't attempt to try the > "A ?" query. This means that the outgoing mail sits in the queue forever. > > This is not a particularly useful default behavior. > > I have no control over austinenergy.com's DNS. It has nothing to do > with my ISP. I am my own ISP, which is why I spent some time looking > into this failure, to determine if it was a problem on my end. It is, > because I installed a broken sendmail. > > The success of the internet has often been attributed in part to the > philosophy stated in RFC 791. I quote: > > "The implementation of a protocol must be robust. Each > implementation must expect to interoperate with others created > by different individuals. .... > In general, an implementation must be conservative in its sending > behavior, and liberal in its receiving behavior." Too bad the people who wrote these broken DNS servers didn't follow the rule. > Burying a "we are correct" manifesto in some README and enforcing > a default "correct" behavior results in breaking email connectivity. > > It would be better to, perhaps, default to working, which I would > prefer over it being silently, secretly and smugly "correct". > If there really is a need to convert the world, syslog warning > entries might be a less unfriendly way to alert the unwashed masses > of the egregious violations of "correctness". The issue is that the server is reporting a _transient_ failure. That is, it's telling us that if we wait and try again later, we might get a correct response. How do we know if it is a permanently broken server or one that really is having a transient problem that will be fixed soon? See 5.2.3 of RFC 1034. Funny thing is that austinenergy.com seems to have one NS that deals with AAAA queries in an OK-way and one that doesn't. -- Crist J. Clark | [EMAIL PROTECTED] | [EMAIL PROTECTED] http://people.freebsd.org/~cjc/ | [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message