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DNS Issue

Lafflin asked
I have an issue where at a branch office with it's own DC the computers stop resolving names. When I renew the the IP it's fine again....it seems to be happening on all the computer in the office. I have sat at a PC and watched as it could not resolve a hostname...I then RDP'p into the DC that serves it's DNS and was successfully able to resolve this hostname and see the A record listed in DNS manager. Yet I am unable to resolve it until I refresh && renew the IP.....
Some of the things I have checked are DNS replication (by looking at SOA serial #), I have checked that the DNS server is the local DC, I have ensured that new A records are replicated.  I'm out of ideas and this is killing me. My users randomly and sudenly are not longer to print because the printer hostname can't be resolved. Any good ideas are greatly appreciated as I am stumped.
Watch Question

When you say "refresh and renew the ip" do you mean the ip of the PC?  Or the DNS?  I wouldn't expect your DNS to have a dynamic ip?

Also, when you see the A record, has its TTL expired?


I mean the client PC. The TTL looks good as well....I have a theory that because this DC was multihome (no idea why the guy before me would do such a thing) that it was causing the issue, I had disabled the 2nd NIC towards the begining of troubleshooting, but it did't seem to help, however I am begining to think that after disabling the 2nd NIC I have to restart the DNS server service or restart the PC so I have done that and I am going to continue testing to see if the DNS stays stable. Ofcourse this is still just a theory and I might find that it has nothing to do with it at all.....I'll be sure to post back in the mean time I am still very grateful for anyone elses idea's.


when I said "reastart the PC" I meant the DC.

Well, I don't have a solution, but perhaps some other places to look.

Instead of release/renew the ip, what happens if you just do IPConfig /FlushDNS on the PC?

Does IPConfig /DisplayDNS show anything interesting on the PC?

And when the pc is failing to resolve names does NSLookup hostname give a useful error message?


well the flushing dns is what I use to watch it go from resolving to not...on subsequent tries it does not begin resolving again until I release/renew.
displaydns doesn't show anything useful.
I hadn't tries the nslookup....when I get back to test a bit later I will try and report back.
If you ask me, your removed NIC adapter plays a role.
It might be, that DNS Query comes IN via active NIS, while DNS response travels OUT to client via non-present old NIC adapter. The behaviour might be random.

I suggest you define default OUT adapter on SERVER:

First, list routes and adapters in use:

route print

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You'll see something like this:

Interface List
 16 ...00 30 84 28 7a 08 ...... Realtek RTL8139/810x Family Fast Ethernet NIC #2

 13 ...00 18 e7 08 7f 6f ...... Realtek RTL8139/810x Family Fast Ethernet NIC
 10 ...00 19 99 42 eb 1e ...... Intel(R) 82566DM-2 Gigabit Network Connection
  1 ........................... Software Loopback Interface 1
 14 ...00 00 00 00 00 00 00 e0  isatap.{F4868B7C-9461-4005-A21C-FE8E56ABF7F9}
 11 ...02 00 54 55 4e 01 ...... Teredo Tunneling Pseudo-Interface
 12 ...00 00 00 00 00 00 00 e0  6TO4 Adapter
 24 ...00 00 00 00 00 00 00 e0  Microsoft ISATAP Adapter #2
 17 ...00 00 00 00 00 00 00 e0  isatap.{3856EEC5-9958-47CE-9B2A-6E04CC49C3BD} 

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- Note the GATEWAY of this route and write it down!
- Note adapter ID (first line) of the NIC, which you want ot use for outgoing traffic
Then temporarily DELETE default route for outgoing traffic:

route delete

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Then recreate this default route, with same settings as before, with only difference to specify outgoing NIC adapter, too:

route add mask IF 10 -P

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(just use your GATEWAY address instead of and interface ID instead of 10)
DO NOT forget to add -p at the end, which will make this route permanent, otherwise it won't survive reboot.


Thanks Labsy, it looks like it's stable now and I didn't have to add the manual default route after disabling the NIC and rebooting the server.
Your input is still both useful and appreciated, If I do not end up needing this it is still good to have as a reference.