1 hour subdomain failures

[Michael Voight]

John Studarus wrote:
> 
>         I've been tracking down a intermittent
> name server problem from a single caching DNS server.
> This caching DNS server will oscilate between
> being able to answer queries and not being able
> to answer the queries for hostnames in the subdomain.
> The oscillations are exactly two hours in total
> length (one hour it works, for the next hour
> it is broken).
>         When I say it is broken I mean that when
> we send a query we never get a packet in reply.
> When I perform the query via tcp the socket closes
> right after the query.  (I've been modifying the
> code to dnsquery for these tests).
>         We have been monitoring several caching
> name servers and this is the only server that has
> this problem!
>         Some more details...  The ttl for the NS
> record for this subdomain is 1 hour.  The ttl for
> hosts in this subdomain is 6 minutes.
>         Could it be that when the NS record
> expires (after 1 hour) the caching server waits
> for an hour before it contacts the authoritative server
> again? 

This sounds broken. After TTL expires, the server should send another
query. What version of BIND? Is the failing one identical to a non
failing one?

Michael 

Michael