External resolve / internal don't

  • Thread starter Thread starter Geraint
  • Start date Start date
G

Geraint

We have a domain running over a WAN with each subnet
containing it's own DC and DNS server. All on Win 2k SP3.
Just recently one of the subnets is experiencing
following problem:
Clients can resolve external names and FQDN for internal
computers but not the short internal names, (they used to
resolve OK).
The DNS server itself can resolve short internal names.

Nothing has changed on this server that I know of and no
errors are reported in the event logs. I have re-
installed DNS on this server but still the same.
The server is multi-homed with one card to the DSL router
and one to internal LAN. Both are set up as per MS
recommendations for multi-homed.
Other info:
DHCP is set up for clients, supplying internal and
external DNS servers. DHCP working OK (ipconfig/all OK).
All required records are present in DNS forward/reverse
lookup zones.
DNS has forwarding set up for 2 external DNS's.
DNS listening on both cards (I know not recommended but
we have this set on all our DNS's as they don't work
unless we do!).

It looks like DNS is just not reading the records in the
forward lookup zone (out of date/not valid???).

Any ideas.

Geraint
 
What does nslookup on the clients show?
If you try pinging internal names with a "." at the end (e.g. clientA.),
does it resolve then? If it does, you may have suffix issues. Try adding
your internal domain names to the "append these DNS suffixes..." option in
TCP/IP. Then net stop and net start dnscache and test again.

Lastly, since you have multiple DNS servers, it would be helpful if you
could describe how they are configured, both in TCP/IP and in DNS
properties.

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
Microsoft MVP - Directory Services
www.readymaids.com - COMPLETE SPAM Protection
www.akomolafe.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon
 
G> Nothing has changed on this server that I know of [...]

That's because the behaviour that you are talking about is implemented
by the *clients*. The DNS protocol and DNS servers deal solely in
fully-qualified domain names. The conversion of "nicknames" to
fully-qualified domain names is done by the DNS *clients*.

G> DHCP is set up for clients, [...]

And this is probably *how* you managed to change the configurations of
all of your DNS clients.
 
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