KMS Activation

Question

Hi experts

When i use the below syntax to activate one of my windows server i am getting the below error.

C:\Windows\system32>cscript C:\Windows\System32\slmgr.vbs -ato

Activating Windows(R), ServerDatacenter edition (000765789-7yu8-u8ik-n458-87900oi6934c) ...
Error: 0xC004F074 The Software Licensing Service reported that the computer could not be activated.
No Key Management Service (KMS) could be contacted. Please see the Application Event Log for additional information.

When i am trying to telnet my kms server on port 1688 i am not able to.
What other ports do i need to allow other than 1688. is 1688 port bidirectional or unidirectional

2. what is the time frame for kms client to communicate with kms server. for example i want to activate my server today and close the ports. if i need to reopen the ports after how many days do i need to

source link； https://social.technet.microsoft.com/Forums/windows/en-US/8f287e39-94cd-4ad0-bb44-ab3ebe811f20/kms-activation?forum=winservergen

Answer 1

Hi Glenn,

Make sure the KMS client can reach the server by FQDN. If no DNS server is available, add new HOSTS entry to allow IP to FQDN resolution

Open firewall from KMS source clients to the central KMS server on TCP port 1688

What’s more, does the kms server show the incoming request in the event log, and that it is sending a response? Test the port with a telnet connection as outlined in the following link.

http://support.microsoft.com/kb/974998

There is not a duplicate IP anywhere on the network is there? Was the server a clean install or was it from an image? If it was an image could it have a duplicate GUID?

Besides, the KMS server won't start activating licenses until the count reaches 25.

A similar case:

https://social.technet.microsoft.com/Forums/windows/en-US/546c2ffc-83ff-4357-ab42-81468196f8d9/kms-issue-kms-has-not-been-working-since-january?forum=winserverManagement

About your question in the last paragraph:

“what is the time frame for kms client to communicate with kms server?”

They have to connect every 180 days. However, the KMS server must have a certain number of activations on it to activate the computer, those activations stored on the KMS server expire every 30 days. Its confusing so an example is in order:

The activation threshold -- essentially how many computers have to activated to the KMS server in the last 30 days -- for workstations is 25. Clients, I think, attempt to reactivate every 7 days. So, if you have more than 25 permantent KMS activated workstations on the same LAN as the KMS server, then a roaming laptop could be out for 180 days at a time. However, if you have less than 25 workstations on the same lan as the server, then a condition could arise where that laptop would not be able to activate if there haven't been 25 'check ins' in the last 30 days.

If you are talking about workstations that will permanently move to another location, then the only way to do it is to create a VPN connection at least every 180 days.

Regards

Answer 2

Hello,
The KMS client queries DNS for the KMS host(DNS record should also include the port to be used, the default is 1688), this also tells the KMS client which port to use. the port is configurable. The port needs to be bi-directional, the KMS client queries the KMS host, the KMS host has to respond to the KMS client.

Link to registry setting for setting the KMS post other than the default of 1688
https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/dn502532(v=ws.11)