+A RHEL host has default firewall rules that prevent any Open vSwitch tunnel
+traffic from passing through. If a user configures Open vSwitch tunnels like
+GRE, VXLAN, LISP etc., they will either have to manually add iptables firewall
+rules to allow the tunnel traffic or add it through a startup script (Please
+refer to the "enable-protocol" command in the ovs-ctl(8) manpage).
+