The DNScache package includes a dnstrace tool that's designed to debug
these problems. ``dnstrace 15 briefme.com 192.5.5.241'' shows that
* one of the briefme.com servers is down;
* one of the servers says briefme.com MX remove-it.com;
* the other three servers listed by the parent say briefme.com MX
mail.remove-it.com and briefme.com MX 209.191.19.113; and
* yet another server, not listed by the parent but listed by some of
the children, also says briefme.com MX mail.remove-it.com and
briefme.com MX 209.191.19.113.
There are, by the way, many subscribers to the qmail list whose domains
show similar inconsistencies between DNS servers.
Mark Delany writes:
> I get different results when querying that domain with dnscache and bind.
Random in both cases. An initial query to an empty cache is more likely
to get the mail.remove-it.com and 209.191.19.113 results, because that's
available from three out of the four immediately accessible servers; but
a query to an active cache is more likely to get the other result, which
has a much larger TTL.
---Dan
