It could happen. I saw this issue couple of times, not only on domain controllers, but also on other domain joined computers.
The cause of this problem is the Network Location Awareness service. We know, that this service is recognising network location based on gateway and is trying to locate AD server thru port 389. Well, when gateway is changed or no server connection true port 389 is available, we have a new network location – by default it is Public.
Anyway, it can happened that NLA service starts before the AD services are started (or before DC is reachable on a non DC server). In this case, we will have public network profile on DC or domain joined computers. If firewall is enabled, most of network services will not run as the firewall for the Public profile is almost closed.
We have few possibilities to solve this situation. Maybe the most simple way is to restart the server, but I don’t know if I can restart the server at this moment and what was the original cause of the problem – maybe it will reappear. The second option is to disable / reenable the NIC adapter and in most cases, it will solve the issue. We will get the same result if we just restart the NLA service – this is a better way.
In some cases, you cannot connect to the computer for some reason. In this case, I use PowerShell remote session to solve the problem.
Here are the steps:
Enter-PSSession ComputerName (establish connection to computer with the problem)
Get-NetConnectionProfile (this will show you your current location profile – if this is the source of the problem, the location will not be Domain)
Restart-Service nlasvc (this cmdlet will restart NLA service; after this step you should see Domain network profile)
Get-NetConnectionProfile (just to check if the solution works)
Exit-PSSession (disconnect form the remote computer)
Based on my experience, this solution works always. Some administrators also suggest to change start option for NLA service to Automatic (Delayed Start). I am not sure if this is a good solution; be careful with it. Maybe you can do it in cases where this error is frequent (better: search for the original cause and solve the problem)
Of course you have heard about the new malware, which yesterday created a lot of problems in industry. Unfortunately it is not an unknown problem.
Microsoft released a patch for this type of vulnerability already in March, but it seems once again that administrators are not patching their systems.
So, if you haven’t patched your systems at least every month, if you haven’t patched your system from March, is time to do it. And don’t forget to have a good defense system (antivirus and other prevention mechanisms). Update them to!
You can find additional information in this link.
Here is a link to post how was neutralized and who did this.
Anyway, we have already a version 2.0; you can read about this version here.
Again, please patch your systems! This update will solve a vulnerability. And don’t forget: this is not the first malware who was written on known vulnerability – patch your systems constantly!
Additionally, please disable SMB1 protocol – it is not new that it is not secure. Here and here are some guidelines how to do it via GPO.
Sometimes you will have to transfer DHCP settings via netsh command. This could be useful for a couple of reasons and it is fine to know how to approach it. Anyway, this is the quickest way to do a DHCP migration.
First you have to login to source server (it could be also a failover clustered DHCP service) and open CMD as Administrator. Then you have to enter in netsh mode with typing:
Now you have to select server with typing:
dns server \\servername
Where servername is the name of the old DHCP server or clustered service name. This will connect you to DHCP server and you are ready to export settings with this command:
export filename all to export the entire configuration or
export filename 192.168.222.0 to export only a scope configuration (in my case 192.168.222.0)
Of course, you have to replace the filename with full path and name of the file where you want to save exported data. This file now must be transferred to target – new server and we are ready to import the configuration. Of course, priory you import the configuration, the new server has to be authorized in AD. To begin an import procedure, we have to do the same steps as on the old server; open command prompt, enter into netsh mode and select DHCP server. After this, we have just a step to import settings with this command:
Import filename all to import all settings or
Import filename 192.168.222.0 to import just a scope
That’s all. Just be sure to double-check if the import did its job, disable and unautorize the old server (you can do it also with netsh: netsh dhcp delete server ServerIP). Of course, don’t forget to uninstall the service on the old computer.
You have finished. Good work!
A lot of us, in small environment, is using Windows backup to backup all servers. To be honest, it is a good enough solution, but we have problems with reporting. For me, as an administrator, it is very important to know if a backup was successful or not. There is still another problem, that we have many small environments to check and it would be nice to receive reports thru mail.
As there I didn’t find a solution, I wrote a script, which runs as scheduled task (weekly or daily – as you prefer) and E-Mail me all errors on backup jobs in last X hours. It is working for me and now I am more secure that everything in the system is going in the right way. Be careful how you will use the script; it should be used on any server where you run Windows backup and if you are using Exchange for sending mails take care on authentication or create relay connector to allow the script to send an E-Mail.
Script could be downloaded here..
For any administrator, who want to use any kind of free tools to have better access or monitor some functionalities in Windows environments, here we have a list of many free tools. Just look which is usable for you and use it:
And please, test it in test environment prior you use it in production. Many times tolls are not exactly the same as you expect..