3Com 10014299 manual Address of a Tunnel Must be configured Interface, Setting the Network

		Configuring GRE 639
Setting the Destination	After a tunnel interface is created, the destination address of the tunnel channel
Address of a Tunnel	must be configured
Interface	The destination address is the address of the physical interface where the GRE
	packets are received. The source address and destination address of a tunnel
	interface uniquely identifies a channel. These configurations must be done at both
	tunnel ends. The source address of one end must be the destination address of the
	other end.
	Perform the following settings in the tunnel interface view.
	Table 689 Designate the Destination Address of Tunnel Interface
	Operation	Command
	Designate the destination address of	destination ip-address
	tunnel interface.
	Cancel the destination address of tunnel	undo destination
	interface.
	By default, no destination address of the tunnel interface is configured.
Setting the Network	Two private networks are interconnected by a GRE tunnel. This kind of connection
Address of the Tunnel	is like a virtual “direct” connection between two private networks. To establish a
Interface	direct route between these two networks, you must configure the network
	address of the tunnel interface and make sure that the network addresses at both
	ends of the channel are in the same network segment. Thus, the system can
	produce a direct tunnel route automatically.
	Perform the following settings in the tunnel interface view.
	Table 690 Set the Network Address of Tunnel Interface
	Operation	Command
	Set the IP address of tunnel interface.	ip address { ip-address mask
		unnumbered interface-type
		interface-number }
	Delete the IP address of tunnel interface.	undo ip address { ip-address mask
		unnumbered interface-type
		interface-number }
	Set the IPX address of tunnel interface.	ipx network network-number
	Delete the IPX address of tunnel interface.	undo ipx network
	By default, no network address for the tunnel interface is configured.
Setting the	It is stipulated in RFC 1701 that if the key field of the GRE header is set, the
Identification Key Word	receiving side and transmitting side check the identification key word of the
of the Tunnel Interface	channel. Only when the set identification key words at both ends of the tunnel are
	totally identical can the check pass, or the message will be discarded.
	Perform the configurations in the tunnel interface view.
	Table 691 Set the Identification Key Word of Tunnel Interface
	Operation	Command