DNS client suddenly stopps working

  • Thread starter Thread starter Dominic Wyss
  • Start date Start date
D

Dominic Wyss

on some Windows2000 and WinXP clients in our Domain the DNS
client/resolver just stopps working. a reboot of the PC makes
it work again.
interestingly this happens only to our own domain! other domain
lookups (i.e. internet servers) still work!

our domain is intra.ourdomain.ch
-ping server1.intra.ourdomain.ch stopps working after some hours
of uptime: could not find host ...
-ping server1 still works (I think thats because of the Netbios resolver)
-ping www.otherdomain.com still works.
-with nslookup it works always, so it's not a server problem.
-putting the server into the hosts file would solve the problem,
but thats not the idea...

for Windows servers this is not a big deal, they can be resolved
over Netbios. but all other servers are not reachable anymore until
a reboot of the client is done.

any hints?
thanx
Domi
 
Dominic Wyss said:
on some Windows2000 and WinXP clients in our Domain the DNS
client/resolver just stopps working. a reboot of the PC makes
it work again.
interestingly this happens only to our own domain! other domain
lookups (i.e. internet servers) still work!
Click to expand...

Classic symptom of someone setting BOTH an internal
and an external DNS server in the machine's client IP
properties (on the NIC\IP).

ONLY internal DNS servers should be used for internal
(especially domain) machines.

To resolve external names, the internal DNS servers
should forward (to the ISP or a firewall) to an external
resovling DNS server.
 
Classic symptom of someone setting BOTH an internal
and an external DNS server in the machine's client IP
Click to expand...
does this mean that Windows is suddenly changing from
first to the secondary DNS server for resolving hosts?
whats the reason for switching?
 
HM> To resolve external names, the internal DNS servers should forward
HM> (to the ISP or a firewall) to an external resovling DNS server.

.... or just perform the query resolution themselves.
 
Dominic Wyss said:
does this mean that Windows is suddenly changing from
first to the secondary DNS server for resolving hosts?
whats the reason for switching?
Click to expand...

(correct) Server is busy or gets rebooted or some such
 
thanx for the hint. it seems that the affected hosts indeed
do have an external server as second DNS.
 
Remove the external DNS server from ALL NIC/IP
properties (including servers) and add a forwarder
to your internal DNS servers (if needed.)

All clients will query internal servers which will
then either answer directly or query the external
names on behalf of the clients.

Remember that "servers" are clients too!

AD DNS
1) Dynamic for the zone supporting AD
2) All internal DNS clients NIC\IP properties must specify SOLELY
that internal, dynamic DNS server (set.)
3) DCs and even DNS servers are DNS clients too -- see #2

Restart NetLogon on any DC if you change any of the above that
affects a DC.

Ensure that DNS zones/domains are fully replicated to all DNS
servers for that (internal) zone/domain.
 
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