I finally managed to get air print working where the printer is on a wired port and clients are wireless. I have wireless clients on VLAN 101 and wired printer on VLAN 100. The APs (AOS10) and switch (6100) they connect to are Central managed and the APs are trunked to both the printer wired VLAN and wireless VLAN. My L3 device for inter-vlan routing is a FortiGate firewall. What I found was the printer service never showed up in Central, but it found all the clients. I'd already enabled AirGroup in central and allowed the air print server. I finally stumbled across this Aruba guide: https://arubanetworking.hpe.com/techdocs/aos/aos10/services/airgroup/configuration/
There's a heading in there about 'wired and wireless servers' and I had to manually add my wired printer as a server. The wording in this section is not very clear so I wanted to get another opinion. With AirGroup services must you always manually configure your wired connected servers manually? This section seems to imply that Airgroup only works by default when clients and servers are wireless connected.
The switch ports the APs connect to are configured as below. VLAN 100 is my wired VLAN which my printer is on while 101 is my wires VLAN. I assume Airgroup doesn't care if the VLAN 100 is native or 802.1q for discovery to work? :
interface 1/1/1
description AP
no shutdown
vlan trunk native 100
vlan trunk allowed 100-101
apply fault-monitor profile default
loop-protect
exit
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