R3303-HP HSR6800 Routers Layer 3 - IP Services Configuration Guide

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Ste
p
Command Remarks
8. Enable the GRE packet
checksum function.
gre checksum
Optional.
Disabled by default.
9. Configure the key for the GRE
tunnel interface.
gre key key-number
Optional.
By default, no key is configured for
a GRE tunnel interface.
The two ends of a tunnel must have
the same key or have no key at the
same time.
10. Specify a value for the
Recursion Control field in the
GRE header.
gre recursion recursion-value
Optional.
By default, the value of the
Recursion Control field in the GRE
header is 0.
11. Configure a route for packet
forwarding through the
tunnel.
See Layer 3—IP Routing
Configuration Guide.
Each end of the tunnel must have a
route (static or dynamic) through
the tunnel to the other end.
12. Return to system view.
quit N/A
For information about tunnel interfaces, more configuration commands in a tunnel interface, and the
expedite termination function, see "Configuring tunneling."
For more information about commands interface tunnel, tunnel-protocol, source, and destination, see
Layer 3—IP Services Command Reference.
Configuring a GRE over IPv6 tunnel
Configuration guidelines
Follow these restrictions and guidelines when you configure a GRE over IPv6 tunnel:
• Deleting a tunnel interface also deletes the functions configured on this tunnel interface.
• The source address and destination address of a tunnel uniquely identify a path. You must configure
the tunnel source address and destination address at both ends of a tunnel and the tunnel source or
destination address at one end must be the tunnel destination or source address at the other end.
• 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.
• You can enable or disable the checksum function at both ends of a tunnel.
{ If checksum is enabled at the local end but not at the remote end, the local end calculates the
checksum of a packet to be sent but does not check the checksum of a received packet.
{ If checksum is enabled at the remote end but not at the local end, the local end checks the
checksum of a received packet but does not calculate the checksum of a packet to be sent.
• To configure a route to a destination over the GRE tunnel, configure a static route, using the
destination address of the original packet as the destination address of the route and the address
of the peer tunnel interface as the next hop.