Protocols and standards, Configuring a gre over ipv4 tunnel, Configuration prerequisites – H3C Technologies H3C S10500 Series Switches User Manual
Page 195: Configuration guidelines, Configuration procedure
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Protocols and standards
•
RFC 1701, Generic Routing Encapsulation (GRE)
•
RFC 1702, Generic Routing Encapsulation over IPv4 networks
•
RFC 2784, Generic Routing Encapsulation (GRE)
Configuring a GRE over IPv4 tunnel
Configuration prerequisites
•
On each of the peer devices, configure an IP address for the interface to be used as the source
interface of the tunnel interface (which can be a, for example, VLAN interface or loopback
interface), and make sure that this interface can normally communicate with the interface used as
the source interface of the tunnel interface on the peer device.
•
Create a service loopback group, specify its service type as tunnel, and add an available Layer 2
Ethernet port to the service loopback group. For more information about the service loopback group,
see Layer 2—LAN Switching Configuration Guide.
Configuration guidelines
•
The source address and destination address of a tunnel uniquely identify a path. They must be
configured at both ends of the tunnel and the source address at one end must be the destination
address at the other end and vice versa.
•
Tunnel interfaces using the same encapsulation protocol must have different source addresses and
destination addresses.
•
If you configure a source interface for a tunnel interface, the tunnel interface takes the primary IP
address of the source interface as its source address.
•
When configuring a route through the tunnel, you are not allowed to set up a static route whose
destination address is in the subnet of the tunnel interface. Instead, you can do one of the following:
{
Configure a static route, using the address of the network segment that the original packet is
destined for as its destination address and the address of the peer tunnel interface as its next
hop.
{
Enable a dynamic routing protocol on both the tunnel interface and the router interface
connecting the private network, so that the dynamic routing protocol can establish a routing
entry that allows the tunnel to forward packets through the tunnel.
Configuration procedure
Follow these steps to configure a GRE over IPv4 tunnel:
To do…
Use the command…
Remarks
Enter system view
system-view —
Create a tunnel interface and enter
tunnel interface view
interface tunnel interface-number
Required
By default, a device has no tunnel
interface.