show mdns-sd cache, chromecast mirror

[JustTakeTheFirstStep]

We are trying chromecast mirroring.
Mirroring almost always fails and sometimes succeeds.
The cache data is different when failing and when succeeding.
Can someone guess why mirroring fails??

WLC : 9800-40
Version : 17.3.8a
Chromecast : vlan 207
device : vlan 144

[marce1000]

 - Very tough one : as the issue is apparently intermittent I would try the advisory release :
            https://software.cisco.com/download/home/286316412/type/282046477/release/Cupertino-17.9.4a

                        and check if that can bring improvement , 

 M.

[JustTakeTheFirstStep]

I downgraded to 17.3.8a from the latest release of 17.9.4a.

This is because there is an mdns link local bug in 17.9.4a.

https://bst.cisco.com/bugsearch/bug/CSCwd59093?rfs=qvlogin

[Rich R]

So you downgraded to 17.3 rather than use the workaround for the bug?
17.3 is already past the End of Software Maintenance date so if what you are seeing is a bug (most likely) it will never be fixed in 17.3 so you've probably shot yourself in the foot.
https://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/ios-xe-17/ios-xe-17-3-x-eol.html
I would go back to 17.9.4a and use the workaround. 
At least then TAC can support you if you still see the issue and get the bug fixed in a later release.