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Intermittent internal DNS resolution issues (AD intergrated DNS)
Hi All
Our DNS servers are all Win 2008R2 domain controllers, we have our main internal Zone mydomain.local plus an additional couple of forward lookup zones that are also AD integrated,
I am seeing an issue were some workstations are not able to resolve DNS records that are in these zones, yet the machine next to them can (all PC's are Win 7), also sometimes these same machines that are not working do in fact work, its intermittent,
I was notified that a web page was not working for a couple of users, when I tried to ping it from their machines I was getting host not found, however on the machines that were working it resolved, doing an IP config showed that they use the same primary DNS server.
if I do an nslookup on the machines that are working I get 2 timeouts before it resolves the name, not sure if that's relevant as it still works, all PC's are Gigabit connected and are on the same physical site as their primary DNS server.
Not really sure how to start troubleshooting this one, had a look on the DNS event log but nothing in there
Anyone got any idea's
Thanks
Our DNS servers are all Win 2008R2 domain controllers, we have our main internal Zone mydomain.local plus an additional couple of forward lookup zones that are also AD integrated,
I am seeing an issue were some workstations are not able to resolve DNS records that are in these zones, yet the machine next to them can (all PC's are Win 7), also sometimes these same machines that are not working do in fact work, its intermittent,
I was notified that a web page was not working for a couple of users, when I tried to ping it from their machines I was getting host not found, however on the machines that were working it resolved, doing an IP config showed that they use the same primary DNS server.
if I do an nslookup on the machines that are working I get 2 timeouts before it resolves the name, not sure if that's relevant as it still works, all PC's are Gigabit connected and are on the same physical site as their primary DNS server.
Not really sure how to start troubleshooting this one, had a look on the DNS event log but nothing in there
Anyone got any idea's
Thanks
ASKER
Hi
Yes all PC's point to our DC's for DNS.
We disable the firewall on all internal machines domain profile.
We did test adding an entry in the hosts file and it fixed it, as soon as we removed the issue come back, however I don't like using hosts file as its hard to manage and doesn't scale, I would prefer to to get to the root cause of the issue
Thanks
Yes all PC's point to our DC's for DNS.
We disable the firewall on all internal machines domain profile.
We did test adding an entry in the hosts file and it fixed it, as soon as we removed the issue come back, however I don't like using hosts file as its hard to manage and doesn't scale, I would prefer to to get to the root cause of the issue
Thanks
Have you done an ipconfig /flushdns on the machines? Are you purging stale DNS records?
also check for network latency between clients and DNS servers, it should not be more than 300msec.
Also you might want to check network settings of your clients like dns suffix, WINS settings, connection specific dns suffix. Also make sure to try fqdn.
Also you might want to check network settings of your clients like dns suffix, WINS settings, connection specific dns suffix. Also make sure to try fqdn.
ASKER CERTIFIED SOLUTION
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ASKER
Latency on our network is sub 1 ms so don't think its that.
Thanks, ill check those articles out
Thanks, ill check those articles out
ASKER
Thanks
Make sure your windows firewall or network firewall not blocking your dns request port no or access software/website port no.
If still issue persists then add host entry in local system host file it is store in (root drive\windows\system32\dri