Another Cisco WLC 9800-L issue

[adamscottmaster2013]

I have two controllers 9800-L running 17.12.4 IOS.  wlc01 is the main controllers serving wireless SSID cciers and cciesec.  wlc02 controller is the anchor controller serving wireless SSID cciesp and cciedc.  The ethernet of wlc01 is sitting in vlan100 (192.168.1.1/24) and the ethernet of wlc02 is sitting in vlan101 (192.168.2.1/24).  The controllers communicated via a layer3 switch that handles layer3 routing, NO ACL.  The dhcp server for cciesp and cciedc SSIDs is being handled by the same layer3 switch.  Everything is working fine but every few days or so, devices that use cciesp and cciedc SSIDs just could not associate with them for around 60 minutes or so.  After sixty minutes, they start working again.  During that outage, under the controller's peer configuration, both controllers showed "data path is down";  However, I could ping from wlc01 to wlc02 and vice versa, so network is NOT an issue.  On the main controller wlc01, I could see the status for cciesp and cciedc as "mobility" but on wlc02, I see nothing during that time.  

I open a TAC case with Cisco and they are reviewing the configuration.  Anyone has run into this issue?  

TIA...

[Rich R]

Take a look at CSCwo64967 in case it matches your setup @adamscottmaster2013 
Note this is not fixed in any current releases yet (it will be in 17.18.1)

FYI: 17.12.5 has been the recommended 17.12 release since May - see the TAC recommended link below.
You can see the main fixed bugs at https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-12/release-notes/rn-17-12-9800.html#resolved-caveats-for-cisco-ios-xe-dublin-17.12.5 but from bug search tool there are least 285 bug fixes in 17.12.5 since 17.12.4 (not all get mentioned in the release notes).

[adamscottmaster2013]

---

@Rich R wrote:

Take a look at CSCwo64967 in case it matches your setup @adamscottmaster2013  

 Thank you @Rich R.  Unfortunately, it does not apply in my situation because "Data Link Encryption" is disabled in the environment.

[Mark Elsen]

  - @adamscottmaster2013   Use the command show wireless mobility summary  ; when the data path is down; and check the logs on the controller (preferred = use a syslog server for capturing logs)

  M.

[Mark Elsen]

 - @adamscottmaster2013    Also check the outputs of these commands :
                                                         show platform hardware chassis active qfp feature wireless punt  statistics
                                                         show wireless mobility summary
                                                         show wireless stats mobility
                                                         show wireless stats mobility messages 

  M.
                                                         

[adamscottmaster2013]

---

@Mark Elsen wrote:

 - @adamscottmaster2013    Also check the outputs of these commands :
                                                         show platform hardware chassis active qfp feature wireless punt  statistics
                                                         show wireless mobility summary
                                                         show wireless stats mobility
                                                         show wireless stats mobility messages 

  M.
                                                         

---

@Mark Elsen:  What am I suppose to look for here with the outputs?

[Mark Elsen]

   @adamscottmaster2013        Look for error messages in this one :     show wireless stats mobility messages 
                                                As far as the other commands is concerned ; look for error statistics with a none zero count
                                                (e.g.)  and or other messages which could be associated with problem conditions (e.g.)

                                                Use the commands on both controllers and of course as usual => validate
                                                the configuration on both controllers with the CLI command
                                                show tech wireless and feed the output from that into Wireless Config Analyzer

   M.