Configuring End-To-End Verification On Both Ends Of Tunnel; Setting Identification Key Of Tunnel Interface - 3Com 3C13636 Configuration Manual

3Com Router 3000 Ethernet Family
Configuration Guide
Delete the IP address of the tunnel
interface.
By default, network address of tunnel interface is not configured.

3.2.6 Configuring End-to-End Verification on Both Ends of Tunnel

As RFC1701 provisioned, if the Checksum Present bit in GRE header is set to 1, then
the checksum field is present and contains valid information. The sender calculates the
checksum according to GRE header and payload information and sends the packet
containing the checksum information to the peer end. The receiver calculates the
checksum of the received packet and compares it with the one in the packet. If they are
consistent, the packet that may be discarded otherwise will be further processed.
Checksum can be enabled or disabled on the two ends of a tunnel as needed. If
checksum is enabled only at the local end, the local end will calculate the checksum of
each transmitted packet but will ignore the checksum of received packets; on the
contrary, if checksum is enabled only at the remote end, the local end will verify the
checksum of each received packet but will ignore the checksum of transmitted packets.
Perform the following configuration in tunnel interface view.
Table 3-6 Enable/disable end-to-end verification on both ends of a tunnel
Enable end-to-end verification on both
ends of the tunnel.
Disable end-to-end verification on both
ends of the tunnel.
By default, end-to-end verification is disabled on both ends of tunnel.

3.2.7 Setting Identification Key of Tunnel Interface

RFC1701 provisions that if the Key Present bit in the GRE header of a packet is set to 1,
the tunnel identification key carried by the packet will be verified between the sender
and the receiver. The verification will fail if different identification keys are used, and the
packet will be discarded.
Perform the following configuration in tunnel interface view.
Operation
Operation
3Com Corporation
3-7
Chapter 3 Configuration of GRE
Command
undo ip address
Command
gre checksum
undo gre checksum