AP association to second WLC

Answered Question
Oct 1st, 2010

Hi

I have a quaestion about a new AP association to secondary WLC.

So, I have two offices, one of them are 18 AP and one WLC and the second office is two WLC and 10 AP's.

THE WLC have the same software version installed.

Suppose that all is configured well.

The scenario is that the WLC from first site failed and all AP's are beginning  association to WLC in the seconde site.

In this reason the AP starts donwloading a image from the WLC in the second site?

Kamil

I have this problem too.
0 votes
Correct Answer by rob.huffman about 6 years 2 months ago

Hi Kamil,

The failover process is described below

Power down the       primary controller to which the AP is currently registered. The AP waits for       the heartbeat time set, which is 30 seconds by default, to detect the failure       of the primary WLC. After this period of time, the AP sends heartbeat messages       seven more times, one per second, in efforts to find the primary WLC. If the AP       does not hear from the primary WLC, the AP registers to an available WLC via       the default process. Therefore, the process to detect the primary WLC failure       and register to the secondary WLC takes approximately 80 seconds. Once the       access point joins the secondary controller, it continues to send the discovery       request to the primary controller in order to determine if the primary       controller is back in operation. This can be determined with the help of the       debug lwapp client packet command.

Note: The heartbeat message is similar to a keepalive message. The AP           heartbeat is set to 30 seconds by default. You can adjust this heartbeat time,           down to 1 second. However, if you have not made this adjustment since the last           time that the AP heard from the WLC, 30 seconds pass before the AP realizes           that it cannot reach the WLC.

If a WLC goes down, all the APs that are registered       to that WLC automatically switch to the other WLCs in the mobility group. When       the primary controller comes back on, the APs fall back to it. However, this       operation takes 30 seconds. During this period of time, the service to the APs       is interrupted as the APs rejoin the primary WLC.

From this excellent doc;

http://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a008064a294.shtml#c4

Cheers!

Rob

Correct Answer by Elliott Shawd about 6 years 2 months ago

The AP only needs to download a new image if the new controller has a different code version. Since you said your controllers were running the same version, your APs would not need to load a new firmware when they are pushed to the second controller.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (2 ratings)
Loading.
Correct Answer
Elliott Shawd Sat, 10/02/2010 - 23:28

The AP only needs to download a new image if the new controller has a different code version. Since you said your controllers were running the same version, your APs would not need to load a new firmware when they are pushed to the second controller.

wkamil123 Sun, 10/03/2010 - 02:55

Hi Elliot,

Thanks for your replay.

Do you have more information about how long it takes AP when is pushed to the second controller and can do operate normally for a user traffic.

Kamil

Correct Answer
rob.huffman Sun, 10/03/2010 - 09:19

Hi Kamil,

The failover process is described below

Power down the       primary controller to which the AP is currently registered. The AP waits for       the heartbeat time set, which is 30 seconds by default, to detect the failure       of the primary WLC. After this period of time, the AP sends heartbeat messages       seven more times, one per second, in efforts to find the primary WLC. If the AP       does not hear from the primary WLC, the AP registers to an available WLC via       the default process. Therefore, the process to detect the primary WLC failure       and register to the secondary WLC takes approximately 80 seconds. Once the       access point joins the secondary controller, it continues to send the discovery       request to the primary controller in order to determine if the primary       controller is back in operation. This can be determined with the help of the       debug lwapp client packet command.

Note: The heartbeat message is similar to a keepalive message. The AP           heartbeat is set to 30 seconds by default. You can adjust this heartbeat time,           down to 1 second. However, if you have not made this adjustment since the last           time that the AP heard from the WLC, 30 seconds pass before the AP realizes           that it cannot reach the WLC.

If a WLC goes down, all the APs that are registered       to that WLC automatically switch to the other WLCs in the mobility group. When       the primary controller comes back on, the APs fall back to it. However, this       operation takes 30 seconds. During this period of time, the service to the APs       is interrupted as the APs rejoin the primary WLC.

From this excellent doc;

http://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a008064a294.shtml#c4

Cheers!

Rob

Actions

This Discussion

 

 

Trending Topics: Other Wireless Mobility

client could not be authenticated
Network Analysis Module (NAM) Products
Cisco 6500 nam
reason 440 driver failure
Cisco password cracker
Cisco Wireless mode