Core Issue
Remote Edge Access Points (REAP) do not join the controller. The Lightweight Access Point Protocol (LWAPP) debug on the controller indicates a certificate processing error in the join request.
Resolution
This issue is documented in Cisco bug ID CSCsb88424. LWAPP makes certain assumptions about MTU sizes and can only operate in environments capable of supporting packets of 1500 in length without fragmentation. If a REAP Access Point (AP) is connected to the controller over a link with an MTU less than 1500 bytes, the first fragment of the LWAPP join request will be fragmented again. The controller gets the join request in three fragments. The controller can re-asseamble no more than two fragments. Therefore, it re-assembles the first and the third fragment, resulting in a corrupted join request.
As a workaround, make sure that there are no sub-1500 byte MTU links between the controller and the REAP AP. This issue was first found in version 3.1(59) and was first fixed in version 3.2(116.21). To download wireless software, refer to the Software Center. For release notes for Cisco wireless LAN controllers and lightweight APs for release 3.2.116.21, refer to Cisco 4400 Series Wireless LAN Controllers.
Problem Type
Continuous reboot
Products
Lightweight Access Points
Role in Radio network
Root AP
Topology
LWAPP network
SW Features
Remote Edge Access Points (REAP)
Lightwieght Access Point Protocol (LWAPP)
