1. AP offline and found it was due to Echo interval timeout. From the capture packet file, AC did not receive the echo packets of AP.
And also there was record for this from the log--AC.
2. From the capture packet file, the AP-7 sent the echo request packet to AC and kept alive the CAPWAP. But after 06:59:12 the AC received the last packet. There was not any packet from AP-7
3. From the offline record of AP and the log, it is due to the Echo interval timeout.
4. So, it is the quality of network result in the AP offline. From the log of AP, found the port UP/Down at least 30s. E.g: for AP-49:
5. logon the SW that connected with AP-49. Found neighbor information just as below:
6. Check the log of LSW, the port GE0/0/22 UP/Down frequently. And the down time will last at least 30s. The reason was due to the mac-flapping b4ce-f6dd-2c21. When mac-flapping recover, the AP become online.
7. Check the log AC, found that the MAC (b4ce-f6dd-2c21) was for roaming user. It was normal when the user roaming, the MAC of the user will be flapping.
8. Undo the command ” error-down auto-recovery cause mac-address-flapping interval 30” and the issue was resolved.