Wireless Access

Hello,

 

I recently stumbled upon a 3200 controller having 87 active CAP's as I was troubleshooting some other issues. The controller was running version 6.4.3.x and if I'm not mistaken the 3200 platform limit for 6.4 is 32 CAP's/128 RAP's.

 

I encountered quite a few full controllers already but never an overloaded one like this. I was always under the impression that there was a hard platform limit which was being enforced? I would have suspected any additional AP's above 32 would just become inactive? 

 

However somehow this setup did seem to work correctly. We are only seeing issues now after adding a few more AP's which keep constantly rebooting. It's a master-local setup with multiple locals so we should be able to fix this and split them up properly.

#show ap license-usage
AP Licenses
-----------
Type Number
---- ------
AP Licenses 128
PEF Licenses 128
Overall AP License Limit 128

AP Usage
--------
Type Count
---- -----
Active CAPs 87
Standby CAPs 0
RAPs 0
Remote-node APs 0
Tunneled nodes 0
Total APs 87

Remaining AP Capacity
---------------------
Type Number
---- ------
CAPs 0
RAPs 0

 

#3200

Can you post the output of "show ap database"

How many controllers do you have ?
Do you have enabled HA\FF?
Also run the "show AP active" to see active number of APs running on that controller

Get Outlook for iOS

Added the show ap active output as attachment, the master controller does indeed show 87 active AP's. Even more strange is that the no-of-ap threshold limit is showing a negative value of -55, also added to the thread.

 

We are running a mixed environment of 3200/3400/3600 controllers (master is a 3200) so there is enough capacity (total of +-150 ap's). No HA/FF or VRRP has been configured, all AP's are assigned by LMS IP.

 

We made several groups ages ago to distribute the AP's evenly over the different sites/controllers. However the person managing this setup seems to have neglected this and dumped most AP's under the same system profile causing an overloaded master.

 

Can anyone confirm that there is actually a fixed hard limit and that we are possibily hitting a bug of sorts? I still find it very strange that a controller specified for 32 AP's seems to be actually handling 87 AP's.

Edit: I did some more troubleshooting on this issue and found the culprit. As mentioned above, everything is configured with lms and backup lms IP.

 

For some reason, some of the system profiles were not configured with preemption. My guess is that at some point, some controllers went down and everything failed over to the master and stayed there.

 

What is still unclear though is why a 3200 controller is able to handle 87 AP's? Still need some clarification regarding the platform limit. 

 

Please feel free to open a TAC case.  We don't have enough specific information about your issue to determine what is happening here..

I made a TAC case and was assisted by a brilliant engineer who was able to give me a crystal clear explanation on this. :)

 

 For anyone wondering:

 

I have contacted the Engineering resource team to get more information on this matter:

As per their update, in a failover scenario, the 3200 controller can support the APs when centralized licensing is enabled. Since the APs have already acquired a license from the centralized pool, the APs which moved to 3200 controller would still continue to operate successfully. However, if an AP is rebooted in the meantime, they will be not able to come up on the 3200 controller. 
 
For example:
 
If we have a Master- Local setup:-
Master – 3200 Controller
Local – 3400  Controller
 
Let’s say, if we have 100 Licenses in the centralized pool, and if there are 64 Aps in the local controller and we have Master controller acting as BLMS which can support 32 APs and if Local controller goes down, the Master controller can still support 64 Aps + existing APs which are already up on the Master.
 
However if for some reason, if the 64 APs get rebooted, we can bring up only 32 APs on the Master controller. In a failover scenario, the 3200 controller can support APs.
 
However, It is not recommended to have a setup where a lower Model controller acting as a Master controller. If there are more number of APs active on the controller than the specified limit, this might lead to few issues like controller getting crashed etc. The processing power also plays an important role. Hence, we need to configure/need to setup the controllers accordingly.