This is one of the very common question I get from starters, students, admins who follow my blog. They says, the follow my step-by-step guides to install domain controller on the production or demo setup and at the end they can’t connect the computers to the domain. I’m sure if you are already working on domain infrastructure, you also face same experience in your job some times.
So I thought to share some tips to troubleshoot and get your pc connected to the domain.
Read the Error!!!
This is the very best friend of your initial troubleshooting. Read the error carefully. It will give you some clues where to start. It can be simple typo mistake, so first step, read the error twice or more until you get clear understanding, what it says.
Connectivity
To make successful communication between domain controller and pc it should have reliable connectivity. There are lot of ways where it can be interrupted.
1) Local host
To start, first try the ping to local host ip from the pc ( ping 127.0.0.1) if it success it means local pc running with correct protocols and required components. If its not, its first place to start.
2) Ipconfig /all
Try this on both server and pc and make sure client pc got valid ip assign. Make sure its in same range of ip addresses as server so they can talk to each other.
3) DNS
This is very common issue for the joining pc to a domain. Make sure PC is using the domain DNS servers as its primary DNS resolver. Some time you may have uses a valid domain which ends up with .com, .org, net etc. in such case you need to make sure you have correct DNS entries to identify the local server instead of trying to resolve in to public DNS entry.
If all above are checked, then use “ping” from server as well as PC to make sure both can ping to each other ( if firewall is active in pc or server, allow the ICMP traffic temporally before troubleshooting)
If the pings fails then you need to look in to the network level, it can be the cable, vlan configurations, switch port configuration etc.
Time
This is also very common issue I have seen, make sure your domain controller and computer system time and dates are matched. Even you use common time servers some time there can be mismatch due to sync.
Virtualization
If you using virtualization software to build your home lap or even you production environment there are few things you should check. In these virtualization platforms you can setup the virtual networks as per your requirement. So some time even DC and PC is on same network range, those may not be in same virtual network. Make sure the interfaces are correctly assign for the relevant virtual network.
Beware!! Most of the time if we building a test lab with few virtual machines we use to clone them. Even in production environments engineers doing this. Not a long ago I had to look in to problem with joining virtual machines to domain. It was using one of famous virtualization software. So the engineer who setup the system, used to link-clone ( all vm are runs same initial image ) them. But when go to add those computers to domain only 1 of the vm can add to the domain and only one vm can login to DC. In setup there was 10 vm running. So what you think the problem is ? With the link clone it was copying all the network information as well. So if look in to each pc, every one of them were using same ip address, and same mac address. Interesting thing was even all of them are switched on none of them were giving ip duplication error. So if you used “clone” option to build the VM make sure it got unique ip address and mac address.
I believe above tipe will help you to troubleshoot issues with dc connection.
If you have any question feel free to contact me on rebeladm@live.com
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