I am having some network issues and I am struggling to troubleshoot it. We have a single server running S2008R2. It has two nics, one connected to the internet and one on our LAN. It is the DC and it is running:
- RRAS - NAT for internet
- Print Management
Everything was running fine until last week when a second server was accidentally switched on. It was also set up as a DC. I switched that back off, but ever since we've had a raft of problems that I am struggling to fix.
Server internet- inet working fine on server
Ping- Everyone can ping each other no problem
NSLookup- Shows correct IP and name for server & workstations
Login- No logon server available to service your request, you can log in if you keep trying
Internet- Working from Server and some (random) workstations
Shared Drives Network path not found
Network Printers Offline - can go to the print server IP address from a browser
Group Policy gpupdate /force fails, lack of connectivity to a DC
I am thinking something is screwed up with Active Directory, but I don't really know how to trouble shoot, any suggestions would be brilliant :)
The OLD you switched on, what do you plan to do with it? If not needed I would decomm that
How long was that DC off for? How many days?
Could have replicated old data across to the working DC.
Multihoming a DC is fraught with complexities and the re-introduction of a second DC will only cause more complications.
If your current DC is the only DC in the Domain and the old one you turned on is not in anyway still related it should not have had any great impact, however your lack of explaination as to what the other DC's role in this network is/was leaves me wondering what are we dealing with here?
Firstly I would thoroughly recommend that you stop using your DC as an Internet Router and get yourself a proper firewall apart from making your DC a Bullseye on the Internet there are the added complexities of NAT and the Windows Firewall to contend with.
Having spent years working with SBS2000 2003 2008 and now 2011 I can assure you it will make life a whole lot easier and safer.
The Multi Homing will give you severe headaches in the Binding Order department unless you have been meticulous in setting each service up and making sure things are correct such as what NIC is your DHCP binding to?
I suggest you research the topic of Multi Homing a DC on Google you will find all sorts of useful stuff such as this Can DC be multihomed in Windows 2008 Server?
All telling you why it's not a good idea to Multihome your DC.
By all means do it on a stand alone even a virtual one but not on your DC unless you are absolutely certain you understand what your doing.