Do you have VLAN11 added/configured on the router as well?
With controller WLAN in tunneled mode (default & recommended mode), the VLAN11 should only be needed on the controller. Switches and APs don't need to be aware of that new VLAN, except of course the switch between the router and the controller (if there is a switch in between, which is not written in the diagram).
Is the router the 'default gateway' for both VLAN 5&11 (recommended to leave controller 'layer-2'; and not do routing on the controller)?
If not, in which VLAN is the router? And do you have a proper route (and NAT) setup on the router?
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Herman Robers
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If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
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