This was found in the technet forums:
It is not required to wait for the activation from the KMS host. Everytime When a KMS client sends a request to the host mchine it creates an event ID 12288 within the KMS client`s Event Logs. From there as well we can get the CMID information.
Log Name: Application
Source: Microsoft-Windows-Security-Licensing-SLC
Date: 9/21/2011 1:19:56 AM
Event ID: 12288
Description:
The client has sent an activation request to the key management service machine.
Info:
0x0,0x0,<KMS HOSTNAME>:1688,ae3a27d1-b73a-4734-9878-70c949815218,2011/9/20 19:49,0,3,43200,c1af4d90-d1bc-44ca-85d4-003ba33db3b9,5
Here CMID is :ae3a27d1-b73a-4734-9878-70c949815218
This might help you find a solution.