DNS request timed out

[Raj]

Hi All,

I am having a strange issue with nslookup. There are 2 domain names
registered for the company I work for. Windows team manages
apac.company-net.com domian and I (UNIX) manage au.ap.company.com
domain.

Windows guys have configured forwarders in Windows DNS to resolve
au.ap.company.com. So if a windows client tries to access
hostname.au.ap.company.com, windows DNS server forwards the request to
UNIX DNS server. Now the issue is they can resolve au.ap.company.com
hostnames without any issues when the UNIX master DNS server is up and
running. When the master DNS server goes down slave DNS server is not
responding to windows clients queries. But if I login to one of the
UNIX clients and use nslookup pointing server to slave UNIX DNS server
there are no issues. I am not able to figure out why windows clients
are not able to resolve using slave UNIX DNS server.

So we did a tcpdump and found that whenever they use slave UNIX
server, it is appending apac.company-net.com even for
au.ap.company.com hostnames. This is not the case when windows clients
uses UNIX master DNS server. Can somene help me to resolve this issue.

Below is the nslookup tests:


      > server 172.xx.xx.172
      Default Server:  dns2.au.ap.company.com
      Address:  172.xx.xx.172

      > live
      Server:  dns2.au.ap.company.com
      Address:  172.xx.xx.172

      DNS request timed out.
          timeout was 2 seconds.
      *** Request to dns2.au.ap.company.com timed-out
      > live.au.ap.company.com
      Server:  dns2.au.ap.company.com
      Address:  172.xx.xx.172

      DNS request timed out.
          timeout was 2 seconds.
      Name:    live.au.ap.company.com
      Address:  172.xx.xx.237

      >

In the above tests, slave UNIX DNS server is 172.xx.xx.172 and
live.au.ap.company.com's IP is 172.xx.xx.237. It is resolving to the
correct IP address but it's timing out. Please advise why it says DNS
request timed out.

Thanks.