R0106-HP MSR Router Series Layer 3 - IP Services Command Reference(V7)

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GRE commands
gre checksum
Use gre checksum to enable the GRE checksum function.
Use undo gre checksum to disable the GRE checksum function.
Syntax
gre checksum
undo gre checksum
Default
The GRE checksum function is disabled.
Views
Tunnel interface view
Predefined user roles
network-admin
Usage guidelines
The GRE checksum function verifies packet integrity.
You can enable or disable the GRE checksum function at each end of a tunnel as needed. After GRE
checksum is enabled, the sender does the following:
• Calculates the checksum for the GRE header and the payload.
• Sends the packet containing the checksum information to the peer.
The receiver calculates the checksum for the received packet and compares it with that carried in the
packet. If the checksums are the same, the receiver processes the packet. Otherwise, the receiver
discards the packet.
The receiver checks the GRE checksum of a received packet only if the packet carries a GRE checksum,
regardless of whether or not the receiver is enabled with the GRE checksum function.
Examples
# Enable the GRE checksum function.
<Sysname> system-view
[Sysname] interface tunnel 2 mode gre
[Sysname-Tunnel2] gre checksum
gre key
Use gre key to configure a key for a GRE tunnel interface.
Use undo gre key to remove the configuration.
Syntax
gre key key-number