You must have already performed the following in one form or another as well as properly set a STATIC IP. Bear in mind many instructions do not properly show how to commit iptables changes on Photon which then survive reboots.
iptables -A INPUT -p tcp --dport 2375 -j ACCEPT
iptables -A INPUT -p tcp --dport 2376 -j ACCEPT
iptables-save > /etc/systemd/scripts/ip4save