Configuring 802.1q trunk between UniFi AP and Juniper EX switch
Problem:
After configuring 802.1q VLAN trunking on port, according to UniFi Wireless Controller, AP is now in Disconnected or Adoption Failed state.
Diagnosis:
Tap the traffic (e.g. using port reflector). UniFi AP expects no VLAN tagging on native VLAN, tagged packets on management interface will get discarded. If you’ve a lot of DHCP Discover and DHCP Offer packets but no DHCP Request packets, check if your native VLAN packets are not tagged.
Running show ethernet-switching interfaces will probably describe default VLAN as tagged and untagged at the same time:
Interface State VLAN members Tag Tagging Blocking
ge-0/0/1.0 up default 1 untagged unblocked
VLAN2 2 tagged unblocked
VLAN3 3 tagged unblocked
VLAN4 4 tagged unblocked...