LWAPP re-join to WLC

[madelaporte]

I have a remote AP that initially was having trouble connecting to the WLC for the initial join. For some reason, it suddenly decided that it would join. All well and good, it joined, downloaded the new software, and functioned properly. I had to move the AP to another location, and since then, it will not join the WLC.

I can see that the AP is sending a Join request to the WLC, and that the WLC sends a response, but nothing after that. I know the AP also recives the response, but after that, the AP acts like it didn't get anything and reloads.

Any help would be appreciated.

Thanks

Miche

[Scott Fella]

Are you seeing in the log that the AP gets a join response from the WLC? If so, what else does the log show? Is the AP in local or h-reap and what is the link connecting the two sites?

[madelaporte]

I do see the join response from the controller, all i see in the controller is the "successfully sent join response" message, and in the AP, i don't see any mention of receiving the reply, but i can't find a debug option similar to "debug lwapp ap events" for the AP.

As for your other questions, the AP is in local mode, and the link between sites is an routed IPsec link. I'm certain the firewall/router isn't the problem because the AP has already joined the controller, and i can see the join response packet come through the remote ipsec endpoint.

Thanks for your help.

[Scott Fella]

Look to see if the FW is dropping any packets. Are you able to post the log form the AP when it goes through the join proccess? The AP has joined previously, but doens't mean moving the ap to a different location or subnet will always work. What is your ping times from the remote site to the central site where the wlc is located?

[madelaporte]

I've attached the debug output from the AP. Doesn't give you much time to enter any commands before it reboots!!

The "move" was only a physical move, not a network move... It was moved into a server room rather than a colleague's desk, so that would not have anything to do with it.

I've checked the firewall, and i can't see it dropping any packets(and packets dropped are logged). Ping times are ~25ms during normal hours.

Thanks for your help.

Miche

[madelaporte]

Ok, i believe i have found the issue. Fixing it doesn't look so easy.

The LWAPP join request from the AP is a packet 1506 bytes in length. The problem is the MTU for the inter-site tunnel is 1476 bytes.

I can't change the MTU for the inter-site link, as i will break some applications which use the link.

Any ideas as to how i can change the MTU for the AP?

Thanks

Miche