Caching nameserver and odd MX problem

[Kevin Darcy]

This is a bit of a mess. prepaid-phonecards.com is delegated to thebiz.net nameservers, but only iinc.com nameservers are being
published in the zone. The iinc.com domain is the same way in this regard. Also, ns2.iinc.com appears to be a CNAME (it's illegal to
point an NS record at a CNAME), and it appears that zone replication is broken between the iinc.com nameserver(s) and the thebiz.net
nameservers, with the result that the thebiz.net nameservers are serving stale data.

None of this, in and of itself, should be preventing the MX from resolving. I was able to resolve the MX from your server as well as
mine. However, all of the running around that this ugliness is imposing on resolvers (including the one embedded in sendmail) may be
causing a resolver timeout. In modern versions of sendmail, resolver timing values are configurable.


- Kevin

Jason wrote:

> my MAILserver
> mail.cartmanager.net
> is haveing a bugger of a time sending mail to this domain name
> prepaid-phonecards.com
>
> It functions perfectly until the cache for the MX record expires, then will not send any futher mail until I restart my nameserver
> Here is a snip of the sendmail reason for failure
> Deferred: Name server: prepaid-phonecards.com.: host name lookup failure
>
> my nameserver is
> ns.cartmanager.net
>
> I am a little new to detective work on the DNS front, but have read several documents in the list archives.  And have found may
> POSSIBILITIES at to why the domain name may be having trouble.
>
> So far I think I have ruled out many of the list archive suggestions using the "dig" tool.  However, I still cannot find why it is
> failing...
>
> In fact the only thing I have not been able to rule out is that the MX record appears to have a different cache setting then the
> rest of the prepaid-phonecards.com domain name.  My only guess is that my nameserver (named 8.2.3-REL Mon Jan 29 06:04:52 CET 2001)
> is not looking up the MX record due to the fact that it still has other information cached for that domain name.
>
> Is there a way for me to track down what may be wrong.  Its really annoying to have to restart my nameserver (even though I could
> crontab it easily)
>
> And how do I fix it?
>
> Thanks
>     -Jason