strange DNS problem

pckizer at pckizer at
Mon Oct 9 13:02:28 PDT 2006

On 2006, Oct 6, at 04:02, Wojciech Puchar wrote:
> one of my users reporting problem sending e-mail to
> sendmail reports host name lookup failure
> host reports
> [wojtek at chylonia ~]$ host -t mx
> mail is handled by 10
> [wojtek at chylonia ~]$ host -t a
> has address
> has address
> Host not found: 2(SERVFAIL)
> ^^^^^^^^^^^^^
> where's a problem? while hostr is able to get IP addresses but then  
> reports servfail?

What you are seeing is the IPv6 AAAA lookup:

# host -t aaaa
Host not found: 2(SERVFAIL)

Make sure you have the Sendmail option turned on to ignore the  
SERVFAIL messages:

# grep AAAA /etc/mail/
define(`confBIND_OPTS', `WorkAroundBrokenAAAA')

# grep AAAA /etc/mail/
O ResolverOptions=WorkAroundBrokenAAAA

With that, mail should flow fine.

Though I have to admit I am having a similar problem except the host  
is randomly (with a very high probability of it doing so) failing to  
respond at all rather than at least answering SERVFAIL.  With no  
SERVFAIL it appears Sendmail/resolver consider the NS host to be down  
and do not fail through to try and lookup the A record.  [I'm still  
trying to verify that.]


More information about the freebsd-questions mailing list