When the ISG cluster devices are correctly configured, they will start synchronizing the configuration. You can check if the configurations is in sync with the following command:
Cluster1:fw01(M)-> exec nsrp sync global-config check-sum configuration in sync
It can happen from time to time that the configuration of the cluster run out of sync:
Cluster1:fw01(M)-> exec nsrp sync global-config check-sum Warning: configuration out of sync
To solve this issue, you should force the configuration sync (only on the backup device!!!!):
Cluster1:fw02(B)-> exec nsrp sync global-config save load peer system config to save Save global configuration successfully. Save local configuration successfully. done. Please reset your box to let cluster configuration take effect! Cluster1:fw02(B)-> reset System reset, are you sure? y/[n] y In reset ...
After the reboot of the backup device, the cluster should be fully operational and in sync.
Note : when the device prompts you to save the config, enter “n” (no)