failing lookups

[Kevin Darcy]

Offhand, I can think of only 2 reasons why named wouldn't failover to the other nameserver:

1) It's configured to forward with "forward only" and only 1 of the nameserver addresses specified

2) It got a bad response from the other nameserver recently, so it's marked it as "lame" and won't use it for a while.

Of course, this is all assuming that the two nameservers you identified are actually the nameservers published in the NS records of the zone. If the zone is delegated to 2 nameservers, but only 1 of them is published in the zone's NS records, then the zone's NS records, being more "credible" than the delegation records, will be what named uses
to resolve names in the zone. Which might explain why the other, unpublished nameserver is being ignored.

If you had told us the real name of the domain, then I could have checked out this last possibility myself, instead of having to speculate blindly. It's very annoying when people "genericize" or "anonymize" the names of Internet domains that they're having trouble with. It serves no useful purpose and just makes troubleshooting more difficult.

                                                                                                                                        - Kevin

Bob Puff at NLE wrote:

> Hello,
>
> I've recently noticed an oddity with my Bind 8.2.3.  I had two notable occurances in the past two days where lookups to other sites failed on one of my DNS servers, but seemed to work on another.
>
> Further investigation revealed that one of the two nameservers for this given domain appeared to be down.  Bind apparently was trying to query this particular nameserver, and timed out.
>
> Is there a way to play with the config to perhaps modify the timeout value, and have it try the alternative nameserver(s)?
>
> Another somewhat similar problem was found: lookup foo.com.  Ok, returned the IP address.  One of foo.com's nameservers goes down - the one that Bind just got its info from.  Next lookup: test.foo.com.  Bind goes to the nameserver it just got foo.com from, but it's down, so it fails.  It never seems to try the other nameserver(s) for foo.com.
>
> Would upgrading to Bind 9 fix these problems?
>
> BOb