Controllerless Networks

Hello,

I have AccessPoints (318, 315) connect on 2930M Poe Switches (Stacking), Mobility Master and Mobility Controller (7210).

I see on the mobilty master that some access points online and offline, online and offline.

on the 2930 switch I can see 

I 07/31/19 16:55:54 00076 ports: ST2-CMDR: port 3/39 is now on-line
I 07/31/19 16:55:54 00076 ports: ST2-CMDR: port 3/19 is now on-line
I 07/31/19 16:55:54 00076 ports: ST2-CMDR: port 2/33 is now on-line
I 07/31/19 16:55:54 00076 ports: ST2-CMDR: port 2/16 is now on-line
I 07/31/19 16:55:52 00076 ports: ST2-CMDR: port 3/6 is now on-line
I 07/31/19 16:55:52 00435 ports: ST2-CMDR: port 2/33 is Blocked by STP
I 07/31/19 16:55:52 00435 ports: ST2-CMDR: port 3/39 is Blocked by STP
I 07/31/19 16:55:52 00435 ports: ST2-CMDR: port 3/19 is Blocked by STP
I 07/31/19 16:55:52 00435 ports: ST2-CMDR: port 2/16 is Blocked by STP
I 07/31/19 16:55:50 00435 ports: ST2-CMDR: port 3/6 is Blocked by STP
I 07/31/19 16:55:49 00077 ports: ST2-CMDR: port 2/33 is now off-line
I 07/31/19 16:55:49 00077 ports: ST2-CMDR: port 2/16 is now off-line
I 07/31/19 16:55:49 00077 ports: ST2-CMDR: port 3/39 is now off-line
I 07/31/19 16:55:49 00077 ports: ST2-CMDR: port 3/19 is now off-line
I 07/31/19 16:55:42 00077 ports: ST2-CMDR: port 3/6 is now off-line

How can I troubleshoot why the APs flapping?

Greetings

Looks like Spanning Tree (STP) is blocking some ports, can you confirm these are the ports which the APs terminate on?

I 07/31/19 16:55:52 00435 ports: ST2-CMDR: port 2/33 is Blocked by STP

What is the current spanning tree configuration within your deployment?

Also if there is any mesh, ensure there's no loops.

Hello,

no mesh configuration - on the 2930 switch (3x stacking) there are only APs connected

STP is MST

 show spanning-tree

 Multiple Spanning Tree (MST) Information

  STP Enabled   : Yes
  Force Version : MSTP-operation
  IST Mapped VLANs : 1-4094
  Switch MAC Address : 8030e0-eb2cca
  Switch Priority    : 32768
  Max Age  : 20
  Max Hops : 20
  Forward Delay : 15

  Topology Change Count  : 4
  Time Since Last Change : 4 hours

  CST Root MAC Address : 548028-754700
  CST Root Priority    : 0
  CST Root Path Cost   : 2000
  CST Root Port        : 2/A1

  IST Regional Root MAC Address : 8030e0-eb2cca
  IST Regional Root Priority    : 32768
  IST Regional Root Path Cost   : 0
  IST Remaining Hops            : 20

  Root Guard Ports     :
  Loop Guard Ports     :
  TCN Guard Ports      :
  BPDU Protected Ports : 1/1-1/48,2/1-2/48,3/1-3/48
  BPDU Filtered Ports  :
  PVST Protected Ports :
  PVST Filtered Ports  :

  Root Inconsistent Ports  :
  Loop Inconsistent Ports  :

yes STP is working and block but why?  according the log it shows for me then the aps are connect to the port and unconnect