Just got and started using this portable Wi-Fi .
Working fine on Peppermint 5…No problems at all.
But I noticed the router has its own built in Firewall. (This can be disabled).
Questions.:
Leave Router and Peppermint 5 Firewalls active or disable one of them…?.
Jocklad
Personally I don’t bother with the Linux firewall on my home LAN PC’s, but not for any particular ‘reason’ other than laziness … there’s no harm in leaving it enabled as well as the router one, there’s no performance hit that I can distinguish if that’s what you’re asking.
So your call 
DO NOT disable the routers firewall, that’s protecting your whole local network.
Thanks Mark
That clears that up.
Jocklad 
You’re most welcome