The gre checksum command configures end-to-end check between two ends of a tunnel.
The undo gre checksum command removes the end-to-end check.
By default, end-to-end check of two ends of a GRE tunnel is disabled.
This command takes effect only on a GRE tunnel interface.
If the local end is configured with checksum:
The local end calculates the checksum according to the GRE header and payload.
Then the local end sends a packet containing the checksum to the remote end.
The remote end calculates the checksum based on the packet and then compares the result with the checksum contained in the packet.
If the two checksum values are consistent, the packet is processed.
If the two checksum values are inconsistent, the packet is discarded.
If the checksum is enabled on the local end and disabled on the remote end, the local end does not perform checksum on received packets, but performs checksum on local transmitted packets. In the contrary situation, the local end performs checksum on received packets, but not performs checksum on local transmitted packet.
# Configure checksum on both ends of the tunnel between Tunnel 0 of syanemeA and Tunnel 1 of syanemeB.
<sysnameA> system-view [sysnameA] interface tunnel 0 [sysnameA-Tunnel0] tunnel-protocol gre [sysnameA-Tunnel0] gre checksum
<sysnameB> system-view [sysnameB] interface tunnel 1 [sysnameB-Tunnel1] tunnel-protocol gre [sysnameB-Tunnel1] gre checksum