-1

In my environment, i got 2 DCs Windows Server 2012. But when the primary is down i cant seams to login or find the path in the network to access another PC.

I have checked and all the DCs has GC and when i change the DNS in the PC from primary to secondary then it works, it just the PCs are not going to the second when the primary is down which i have set all the PCs with a secondary DNS and i am using static IPs for all PCs and servers.

4 Answers 4

0

If your clients are set to DHCP, then why don't you just add the secondary DC as secondary DNS server, assuming DNS is also running on the secondary DC?

Also, a trick to log a client in when the DC is down is to simply pull the network cable when entering the password.

EDIT i just saw that the IP's are static. Try an ipconfig -flushdns on a client and see if it makes a difference.

3
  • hello, thank you for your reply, i am using static IPs for security reasons and yet if you pull the lan cable and login successfully then you cant see the other PCs in the network or access your shared folders in the NAS Dec 29, 2016 at 10:49
  • that's why I wrote when entering the password. once you are in windows connect the cable again. did flushdns work?
    – bitFuzzy
    Dec 29, 2016 at 13:56
  • I know what u mean. And yes when u connect the cable u cant access anything and when i open nslookup it shows no server but if i swap the secondary dns of the ADC to the primary it will work just fine. Do u have any idea y the lan dosnt go to the 2nd dns?is there a time out to be set to check the primary? Dec 29, 2016 at 15:13
0

First, check your DCs IP configurations. Make sure the secondary DC can see itself as a DNS server for the domain. If it is depending on the offline server for DNS, you will have this problem.

Next, look into "DNS Client Side caching". It may be a timeout issue at the client that has previously seen the primary. http://blogs.msmvps.com/acefekay/2009/11/29/dns-wins-netbios-amp-the-client-side-resolver-browser-service-disabling-netbios-direct-hosted-smb-directsmb-if-one-dc-is-down-does-a-client-logon-to-another-dc-and-dns-forwarders-algorithm/#section7

https://blogs.technet.microsoft.com/stdqry/2011/12/14/dns-clients-and-timeouts-part-2/

1
  • hello, and thank you for your reply, is there a time out setting for that ? and how can you set it up? Dec 29, 2016 at 10:50
0

Whenever I've had problems with authentication, removing the Ethernet connection will force the PC to use cached credentials. So long as that user has logged onto the PC before it should at least get you logged in to troubleshoot, then reconnect Ethernet.

1
  • hi, thank you for your reply, and yes i know it will go to the cash but when you go to the network then you wont see the others or even if you know a path of a folder in another PC then you cant access it Dec 29, 2016 at 10:45
-1

In a deleted answer, you commented that "1st and 2nd they are configured fine and both DCs are pointing to themselves and clients can do nslookup on both server". This configuration is incorrect.

On a domain controller, the first and second DNS servers should be other domain controllers. The third DNS server should be 127.0.0.1. All of your clients should have at least 2 domain controllers as their DNS server.

1
  • hello.. i dont know how it got deleted, anyway, let me explain more, when the PDC is down and you change the main DNS in the lan card to use the secondary DNS then it works fine. so that is why i wonder why the LAN card it will not use the second DNS when the name is doown!!?? Dec 29, 2016 at 10:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.