We have a device (theatre lighting desk) that uses the ETC Nomad software for remote control / mirroring.

Unfortuantely, this software completely lacks the option to point it directly at a target IP, instead, it listens for Broadcasts from the desk itself to establish a connection.

However, this doesnt seem to reliably traverse my switches - even on the same actual switch.....

It belongs on my VLAN 6, and is plugged into a port with VLAN 6 native.  (all ports on this switch are native vlan 6 apart form the trunked uplink).

If i go directly from the devie to a laptop with matching IPs on both ends, the software works.  Laptop and Desk plugged into the same switch - does not work reliably.  It works sometimes, but not often.  Client on WiFi on the same vlan as the desk on LAN - never works.  

I have IGMP snooping, stom control etc etc off on that vlan and the port profiles.  Loopback and all forms of STP are disabled.

It doesnt matter if the desk is set with a static or dhcp.  Doesnt matter if the desks gateway is set to switch SVI or router.

I can remotely access all other devices on the network from that vlan, even across vlans as allowed by my ACLs without any problems at all, regardless of LAN or WiFi.

All switches are on the current release candidate or stable firmware as of today (all firmwars march / april builds)

One final bit of weirdness..... in all scenarious i have tied (desk on LAN, client on LAN, client on WiFi, client on another WiFi, client on another VLAN.....we can ping it and gets a normal ICMP response.

The switch it lives on is my SG2218P

Would appreciate any pointers!