DNS stops responding after Windows Update
Experts-
Recently, like in the last two weeks or so, I've noticed a couple of my customer's servers (2012R2 & 2016) having DNS issues. I'm not sure if it was a recent Windows Update patch or what. The server functions fine after a reboot, then DNS just stops working. All DNS services are running, it just does not return any data when requested...not even if the server itself tries to browse a website or even a local machine. DNS has been working fine for years on these servers, so it's not a setup issue. One is AT&T and one is Comcast, so probably not an ISP issue. Once it stops working, the local clients can't even browse file shares (can't find the server). I reboot the server and it works fine for ~1 week, then stops again. Anyone else having this issue, heard this issue, seen this issue?
Thanks all!
-Joe
Recently, like in the last two weeks or so, I've noticed a couple of my customer's servers (2012R2 & 2016) having DNS issues. I'm not sure if it was a recent Windows Update patch or what. The server functions fine after a reboot, then DNS just stops working. All DNS services are running, it just does not return any data when requested...not even if the server itself tries to browse a website or even a local machine. DNS has been working fine for years on these servers, so it's not a setup issue. One is AT&T and one is Comcast, so probably not an ISP issue. Once it stops working, the local clients can't even browse file shares (can't find the server). I reboot the server and it works fine for ~1 week, then stops again. Anyone else having this issue, heard this issue, seen this issue?
Thanks all!
-Joe
Jacob Durham
What in the event logs? What troubleshooting have you done?
ASKER
Nothing at all in the event logs that I can find. (although not sure I'm looking in all the places things may be reported)
Troubleshooting: restarted all DNS services, changed forwarders to different providers. In the end a reboot fixes it and these are production servers so limited time in looking.
Thanks for the quick response, Jacob!
-Joe
Troubleshooting: restarted all DNS services, changed forwarders to different providers. In the end a reboot fixes it and these are production servers so limited time in looking.
Thanks for the quick response, Jacob!
-Joe
I suspect this isn't a DNS issue, but is another process on the same server that is running amok and resource-starving the machine to the point where DNS can no longer function.
The .Net 4.7.2 patches have been causing some programs to do so. Use a process monitor to look for misbehaving processes.
The .Net 4.7.2 patches have been causing some programs to do so. Use a process monitor to look for misbehaving processes.
ASKER
The only thing I can find in the event logs are a few of these:
"Name resolution for the name <URL> timed out after none of the configured DNS servers responded."
"Name resolution for the name <URL> timed out after none of the configured DNS servers responded."
ASKER
Hi Cliff-
Good suggestion. I was focused on DNS so didn't think that it could be the canary. I'm going to watch processes and specifically Handles to see if there is a memory leak somewhere.
Thanks,
-Joe
Good suggestion. I was focused on DNS so didn't think that it could be the canary. I'm going to watch processes and specifically Handles to see if there is a memory leak somewhere.
Thanks,
-Joe
did you check the LAN drivers as well?
ASKER
Happened again on the Server 2016 system this morning forcing me to reboot it before the office opened. Nothing I can see in the usage of Handles/threads/memory, all normal. Simply DNS just stops working. LAN drivers are up to date. Suggestions on where to look next?
Are these domain controllers or just DNS servers? What other software is running on these machines.
That it is happening across multiple machines and multiple OS versions, yet is not widely reported (it'd make news if it were) makes me want to look at what *is* common across these servers. Usually installed software.
That it is happening across multiple machines and multiple OS versions, yet is not widely reported (it'd make news if it were) makes me want to look at what *is* common across these servers. Usually installed software.
If you use nslookup to query one of the DNS servers while the issue is happening, what response do you get? Does it just time out or return some sort of error?
ASKER
Hey guys, a quick update. There as an Avast AV update recently so I worked with them. They did advise that their technology "Real Site" has been known to cause DNS issues on 'some' servers. I've disabled that functionality in the policy and reapplied it to the systems. Waiting to see if the DNS issue returns. If not, I'll close this case. Thanks for all the replies. Fingers crossed. Freaking security software....always a pain.
ASKER CERTIFIED SOLUTION
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