GRE Tunnel: Used to configure GRE Tunnel and support GRE OVER IP, GRE OVER OSPF, and GRE OVER IPSEC VPN. The settings interface is shown below:

Click Add to show the GRE tunnel adding page as follows:

Tunnel Alias: Add an alias for the number of the tunnel port and customize the alias.

IP Address: Used as the IP address of the new tunnel, the network segment where the IP address is located in the OSPF running network segment.

Zone: The zone where the outbound interface is located. You can select the LAN area or WAN area.

Src Address: The source addresses the actual public network routing of the outbound interface at the source port.

Dst Address: The actual public network routing destination address of the inbound interface at the destination port.

GRE Key: Shared key, which shall be consistent at two ports.

Advanced: Set MTU value, message check, and link-status check, shown as follows:

Click OK[A252] to finish GRE tunnel settings.