gateway from evpn network through real network. The configured nodes will
announce a default route in the EVPN network.
+Advertise Subnets:: Optional. If you have silent vms/CT (for example, multiples
+ ips by interfaces, and the anycast gateway don't see traffic from theses ips,
+ the ips addresses won't be able to be reach inside the evpn network). This
+ option will announce the full subnet in the evpn network in this case.
+
+Exit Nodes local routing:: Optional. This is a special option if you need to
+ reach a vm/ct service from an exit node. (By default, the exit nodes only
+ allow forwarding traffic between real network and evpn network).
+
MTU:: because VXLAN encapsulation use 50 bytes, the MTU needs to be 50 bytes
lower than the maximal MTU of the outgoing physical interface.