Mobility Express Master AP limiting itself to 20 clients

[Some_Guy]

I have some Mobility Express deployments that are managed through Prime Infrastructure. Occasionally I am getting alarms such as the following logged in PI:

Maximum client limit '20' reached on interface '802.11a/b/g/n/ac' of AP 'wrcsap25'.
Maximum client limit '20' reached on interface '802.11a/n/ac' of AP 'sssap24'.

The AP name that gets logged is always the AP that's acting as the ME controller.

Looking at historical client count graph for the AP seems to confirm there is a hard cap of 20 clients:

Subordinate APs are having no problem serving more than 20 clients. Only the Master APs are hitting this client limit.

The Mobility Express Deployment Guide says this:

If there are more than 50 Access Points in a Mobility Express network, the Master AP(running the Wireless LAN controller function) can service a maximum of 20 clients. This limit only applies to Master AP and not any other Access Point in the Mobility Express network.

But I only have 44 APs at one site and 33 APs at the other. Why I am being limited to 20 clients on the Master AP? How do I adjust the limit?

APs are 2800 running ME 8.8.111.0. But from the historical graphs I can see that the problem also happened at a site that used to run 8.7.something.

[patoberli]

I first would try 8.8.120.0 and if that doesn't help, file a TAC. I guess you are hitting a bug or a wrong documentation.
Not sure if that limit is configurable on the Master AP.

[Some_Guy]

@patoberli wrote:

I first would try 8.8.120.0 and if that doesn't help, file a TAC. I guess you are hitting a bug or a wrong documentation.
Not sure if that limit is configurable on the Master AP.

I'm hesitant to bother trying 8.8.120 since the release notes list a whole whopping two resolved caveats - and neither of them sound at all related.

Might try TAC I guess. Just gotta figure out which AP is the one with SmartNet and make it Master first. ;-)

Looking more and more likely I will end up downgrading to 8.5 anyway since 8.8 is just such a dumpster fire overall. Anybody seen this problem on 8.8 solved by reverting to 8.5? As noted above, I also saw it on 8.7.something, dunno about 8.5 though.

[Some_Guy]

Looks like I am probably hitting bug CSCvk42225. Release notes for 8.8.111 and 8.8.120 now list it under Open Caveats.

Bug report for CSCvk42225 says "Status: Fixed" and also "Known Fixed Releases: (0)". So I guess they fixed it somewhere but don't know where they fixed it? Lol quality software development right there.

[patoberli]

That actually happens often, if the fixed release is not yet public. This is more or less the standard for every new bug actually.

My suggestion, create a TAC and tell them about this bug, you might then receive (if already available) a beta update which should fix this. Unless you can wait for 2-4 months until the next version gets probably released.

[Some_Guy · Accepted solution]

Looks like Cisco has apparently added this gem to the release notes at some point:

If there are more than 25 Access Points in a Mobility Express network, the Master AP(running the Wireless LAN controller function) can service a maximum of 20 clients. This limit only applies to Master AP and not any other Access Point in the Mobility Express network.

Which of course completely contradicts what I quoted from the Deployment Guide above. I really wish Cisco would bother to read their own documentation. Their equipment is expensive enough that there is no excuse for all their amature antics. They should be able to afford beta testing before inflicting their idiocy on paying customers.