when one DC is down users can not login due to primary DNS settings

[bookouri]

We have three DCs (server 2012r2), each of them is also a DNS server. DHCP hands out DC1's ip address to clients as their primary DNS. We also have some fixed IP address clients with DC1 as their primary. They all have one of the other DCs as their secondary DNS setting. If DC1 happens to go offline, none of the clients with DC1 as their primary DNS can access their network resources/shares etc. Even if I reboot a client machine (windows 7) the users still can not log back on and get to their shares as long as DC1 is offline. Once DC1 is back online everything is back to normal. All of the DCs are GCs, all are replicating properly, the netlogon shares are all correct and replicated. This seems to be such a basic major problem that I have to think we have something set up wrong somewhere but I can not find anything to explain it. I can find other people having the same problems, but no actual solutions/explanations.

Can anybody tell me what we can do to prevent loss of one DC being able to bring our entire network to a halt?


thanks

 

[markdmac]

Expand out Forward Lookup Zones. Right click on the domain name and choose Properties. Click on the Start of Authority tab (SOA).

Set your Retry Interval to a value like 10 minutes. Systems should failover after that time frame.

Make sure also that all servers are listed on the Name Servers tab.

I hope that helps.

Regards,

Mark

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