We set mode qinq on sm. We can not understand why the tab Current VID Member Set in the AP shows and s-vlan and c-vlan. Screenshot attached S-vlan = 100, all other c-vlan. AP connected to swich, where port only trunk allowed vlan 100.
If AP used QinQ EtherType 0x8100 - dynamic vlan membership show not only s-vlan (operator vlan) but and all other c-vlan (user vlan). If AP used QinQ EtherType 0x88a8 - not work because, after AP used Cisco 2960 which is not understood EtherType 0x88a8. How to solve the problem with the display of unused c-vlan if AP used 0x8100?
You can try 0x9100 for the Cicso, as they use that for stacked VLANs.
The broader question of membership display - if you are having the radio do the applying/removing of the outer QinQ tag, that doesnt happen until the far side of the link. Which means that in the upstream, it becomes QinQ packet once it leaves the AP. So that is why we may learn the inner tag VID as part of the membership table here. It shouldn't affect operation but does let you see all of the tags that we have seen. We could make an improvement to denote them better to show if they are learned/seen Q Tags or QinQ Tags.