DNS Availability

[peterve]

I have a little question :

I have a DNS server which contains the primary zone for my local domain. This server is in the central site.
I have 4 DNS servers hosting the same zone as secundary DNS.
These servers are in the 4 remote sites.

Users from central site are using the primary DNS server, users from the remote sites are using the secundary servers (in their own site)

When you setup the clients TCP/IP configuration, you can set 2 DNS IP addresses : a primary DNS server and a secundary DNS server.
I noticed that, when the primary DNS server is not available, the clients cannot resolve names anymore...
Why doesn't the clients use the secundary DNS IP to send queries to ? What is the meaning of this secundary DNS IP field ? Peter Van Eeckhoutte
peter.ve@pandora.be

 

[wybnormal]

Do you have reverse lookup in your zones? Have you tried to use NSLOOKUP from a remote site and see what server is actually answering or what the error message is? MS DNS rolls to the 2nd DNS *if* the first DNS server doesnt answer. If you get an answer, then it thinks it's happy enough to stop looking. A real pain at times ;-)

From a cmd prompt ( NT or 3rd party tool), use:

C:>nslookup <name>

To check the reverse naming lookup

C:>nslookup <ip address>

One thing is reconfigure the remotes as non-authortive servers. They will get the request and if have the answer great, if not they bump it up the &quot;authortive&quot; server which would be your root DNS server at the main site. The sequence is the non-A server takes your DNS request and then sends to the root for resolution. After that first request, it's in the cache so now your remote DNS would be &quot;authortive&quot; for the same request next time. The clients only talk to the remote DNS so all of this is transparent to to them.

I highly recommend O'Rilly's book, &quot;DNS and BIND&quot; if you want the nuts and bolts of DNS.

MikeS
&quot;Diplomacy; the art of saying 'nice doggie' till you can find a rock&quot; Wynn Catlin

 

[peterve]

Our DNS servers are set up correctly... I only noticed that, when I turn off the first DNS server in my TCP/IP config, there is no FQDN resolution anymore...

About the non-authorative : do you mean setting my remote DNS servers up as caching-only servers ? Peter Van Eeckhoutte
peter.ve@pandora.be