Setting the CSNP Interval

You can set the advertised complete sequence number PDU (CSNP) interval for an IS-IS interface.

isis csnp-interval

Use to configure the isis csnp-interval level for a specified interface. The level can be configured independently for level 1 and level 2.
For LAN interfaces: the default value is 10 seconds, which you probably do not need to change. For WAN interfaces: the default value is 0 seconds or disabled.
On point-to-point subinterfaces use isis csnp-interval with the isis mesh-group command.
Completed sequence number PDUs are sent by the designated router to maintain database synchronization.
Example host1(config-if)#isis csnp-interval 30 level-1
Use the no version to restore the default value.
See isis csnp-interval