ADTRAN 1000R Series - Manual (Page 1156)

Command Reference Guide Tunnel Configuration Command Set
61200510L1-35E Copyright © 2005 ADTRAN 1156
tunnel checksum
Use the tunnel checksum command to verify the checksum of incoming Generic Routing Encapsulation
(GRE) packets and to include a checksum on outgoing packets. Use the no form of this command to
disable checksum.
Syntax Description
No subcommands.
Default Values
By default, tunnel checksum is disabled.
Applicable Platforms
This command applies to the NetVanta 300, 1000R, 2000, 3000, 4000, and 5000 and Total Access 900
Series units.
Command History
Release 9.1 Command was introduced.
Functional Notes
Both ends of the tunnel must have tunnel checksum enabled in order for a meaningful configuration.
When both endpoints have tunnel checksum enabled, a packet with an incorrect checksum will be
dropped. If the endpoints differ in their checksum configuration, all packets will still flow without any
checksum verification.
Usage Examples
The following example enables checksum on the tunnel 1 interface:
(config)#interface tunnel 1
(config-tunnel 1)#tunnel checksum
Technology Review
When enabled, the tunnel checksum will be calculated for each outgoing GRE packet with the result
stored in the GRE header. The checksum present bit will also be set in the header.