Understanding Centralized License Control

Link Setup Between the License Server and License Clients

1. Enable centralized license control on the license server and license clients, and specify the license server address on the license clients.
2. A license client initiates a link setup request to the license server.
3. The license server responds to the request and sets up a CAPWAP tunnel with the license client. Then they can communicate with each other through the CAPWAP tunnel.

The license server supports link setup with a maximum of 32 license clients.

License Synchronization

License synchronization can be triggered in the following scenarios:

• A license client sets up a link with the license server.
• After centralized license control is enabled, load a license file on any AC.
• License information is changed due to license application or release on the network.

In any of the preceding scenarios, a license client reports local license information to the license server. The license server then synchronizes the latest license resource pool information to all connected license clients.

License Application and Release

After license clients set up links with the license server, ACs do not use their local licenses. Instead, the license server allocates licenses to the APs from the license resource pool.

• Applying for licenses
  1. When an AP requests to go online on an AC, the AC determines whether to allow the AP to go online based on the management specifications and remaining licenses in the license resource pool.
  2. The AC reports license information change to the license server.
  3. The license server updates its license resource pool and synchronizes the latest pool information to license clients.
• Releasing licenses
  1. When an AP goes offline from an AC, the AC releases the corresponding license.
  2. The AC reports license information change to the license server.
  3. The license server updates its license resource pool and synchronizes the latest pool information to license clients.

Handling Disconnections Between the License Server and Clients

If a license client disconnects from the license server, the license client performs the following operations:

• Reserve the number of all licenses in the license resource pool, and update the number of remaining available licenses to a value (number of total licenses - number of locally used licenses). The validity period of the license resource pool is 30 days.
• After the license resource pool expires, only local licenses on the license client are available. If the number of licenses in use exceeds the local license specifications, the AC randomly disconnects some APs until the number of licenses in use is the same as the specifications.

Local licenses are those imported on the local AC.

According to Table 1, there are 500 local licenses on AC_2 (license client), and 600 licenses are in use. If the license resource pool expires, the number of used licenses on AC_2 is 100 larger than the number of local licenses. This causes 100 APs to go offline, and the total number of licenses in the pool on the license server is deducted by 500 (local licenses on AC_2).