I cannot find a way to disable Ethernet port on sm like you can with other canopy gear.
Sometimes we feed a building from two towers for redundancy, and that is only way to bring one up and turn another down.
Solution we arrived at for PMP320 gear should work - create a layer 2 firewall rule under Configure->Security that will Drop traffic in LAN interface with ethertype 0806. While that rule is in place it will prevent ARP on the ethernet. (I assume that means BOTH ethernets, haven’t tried to find out yet) A crafty user (read: network admin/engineer) could circumvent it by hand-coding the ARP for your gateway into their router, but for most realistic situations it will cut them off as soon as their router/pc tries to refresh ARP for its gateway.
We apply a few L3 rules as well (samba, etc) but that’s the only L2 rule, so we can just turn L2 firewall on/off to suspend/restore service.
Not the prettiest, most effective, or most manageable solution, but for now it’s acceptable. (script snmpset to toggle L2 firewall to automate suspend/restore, not too difficult)
BTW - the ePMP gear has its own ‘forum’ at http://epmp.community.cambiumnetworks.com which is why there’s no section for it here. (God I hope they merge it into this forum, what they’ve got there right now is irritating at best)
Oh, and wrt your scenario, try sticking something like a $80 Mikrotik router out there, it can load-balance or select between multiple uplinks and provide a handy test/monitor/manage point.
j