I have 2 Server 2008 R2 domain controllers. Both have DNS on them. The other day I sat down at my Windows 7 machine and could not access the internet. I traced it to a Domain controller that had gone down during a power outage and had not come back up. But the machine should still have been able to do DNS through the second DC. An ipconfig /all on the Win7 machine shows that it is registerring one DNS but not the other. The Win7 machine is doing DHCP. Do both DCs have to have DHCP on them? Is there something wrong with the config of the second DNS Any ideas, thoughts or comments greatly appreciated.

which server you have used as dhcp serverDarshana Jayathilake

Server A does both DHCP and DNS and it shows up as the DNS server on the client machine. Server B just does DNS and it is not seen by the client machine.

Is DHCP handing it out? Regards, Dave Patrick .... Microsoft Certified Professional Microsoft MVP [Windows]

ahhh haaa. DHCP has to hand out the DNS. Correct? So the question is how to I configure DHCP to hand out the Secondary DNS address? Can I have DHCP installed on the secondary DC? Thanks for all the comments. WD

Thanks to everyone who responded to my problem. The problem has been solved, my client computers are now seeing both DNS servers. However, it seems to me this may be a bit irrelevant. If the DC with DHCP and primary DNS goes down the the clients won't get IP addresses so they won't be able to make use of the secondary DNS anyway. So is it possible to install DHCP on the secondary DC? Several years ago someone plugged in a wireless router to our network at work, the wireless router had DHCP on it and suddenly a bunch of computers on our network were unable to connect to the network because they were getting IP's from this DLink instead of the corporate DHCP. I only found it because I was walking around with a wireless laptop and noticed a strange wireless signal in one part of the building. The owner of the DLink has never stepped forward to claim his/her router. As always all and any comments greatly appreciated. WD

Hi again nice to hear you solved the first problem. lets talk about the dhcp now,you can configure dhcp failover,there are 2 options 50/50 or 80/20 First i think you should read lots of materials regarding microsoft server,and his roles. check this link first. http://technet.microsoft.com/en-us/library/ee405263(v=ws.10).aspx Renato Kurti CCNA,CCNP Security,CCAI,MCP,MCTS,MCITP:EA,MCT