When Logging into a Windows Domain is SLOW...

Occasionally, logging into a Windows domain can take a long time. We’re talking 5 to 15 minute intervals here, and it’s annoying as all get out. It can be a hair-pulling, annoying and frustrating game just to diagnose properly. Fortunately, the solution is often straightforward.

Disclaimer: It’s worth pointing out that if you’re not sure what a subnet is, or what the difference between a hostname and NetBIOS name is, or between a WINS server and DNS server is, it’s time to hit the books. Seriously.

One symptom of this is through the Event Log. While I avoid the Event Log like the plague, it is useful to help confirm the diagnosis. Look for notations regarding being unable to contact the domain server (despite being able to successfully log in; gotta love those debug statements). If you find it, then you’re on the right track here.

First and foremost, you’ll want to make sure that your computer is pointing to your Windows server’s DNS and WINS services. Oddly enough, this resolves over half the issues when addressed, especially if your server is sitting on a different subnet. Perhaps the wrong information is being provided to your computer via DHCP; if so, you can either hard code the information or make the necessary changes to your DHCP server. Either way, it’s a configuration issue.

What if this doesn’t resolve the issue, however? In this case, we want to provide some hints to our computer to help it along the name resolution process.

To override your computer’s DNS information for a specific entry, we’ll make changes to the system’s host file. Using a plain text editor (such as Notepad), make the following changes to %WINDIR%\System32\drivers\etc\hosts, adjusting the address and name information accordingly to fit your situation:

192.168.1.55     fluffygerbil     fluffygerbil.example.com

In this example, we’ve added our server’s hostname and fully qualified domain name (FQDN) to this text file. Now, we need to flush the DNS cache to make it forget any invalid entries:

ipconfig /flushdns

Next, we need to override your computer’s WINS information. Using the same method, make the following changes to %WINDIR%\System32\drivers\etc\hosts, adjusting the address and name information accordingly to fit your situation:

192.168.1.55     fluffygerbil     #PRE     #DOM:mydomain
192.168.1.55     "mydomain       \0x1b"     #PRE

The syntax for this file is somewhat different. The #PRE command tells Windows to automatically load this line into memory upon startup. The #DOM command tells Windows the name of the domain that this entry belongs to. The second line contains similar information, however it is specific to the Windows Domain itself; to accomplish this, we’ve put quotation marks around the name and added \0×1b to the end, for a total of 20 characters. Now, we need to flush our NetBIOS cache (note the uppercase -R):

nbtstat -R

At this point, simply log out and log back in. Chances are that your 5-15 minute login time has now been reduced to under a minute.