# NSRP Session Synchronization

When you add a new device to an active NSRP cluster, you must synchronize the configuration and files (such as PKI public/private key files) from the primary device in the VSD group or groups to the new device. After the configurations and files are synchronized, you must then synchronize the run-time objects (RTOs). You must also synchronize configurations, files, and RTOs after a member of a cluster becomes unsynchronized for any reason.

NSRP RTO Synchronization and NSRP Session Synchronization: Select either or both options if you want the device to send and receive RTOs and sessions.

NSRP Backup Session Timeout Acknowledge: After a session is established on the primary device and synchronized to the backup, throughput continues to refresh the timeout value on the primary. However, there is no traffic flowing through the backup to refresh the session timeout there. Although the timeout for a session on the backup is 8 times longer than that on the primary, there is a chance that a very long session can timeout on the backup although it is still active on the primary. Select this option if you want the backup to refresh its sessions before they time out by sending a L2 ACK packet over the HA link to the primary when the timeout value for the session on the backup approaches zero. If the session is still active on the primary, it will signal the backup to refresh the session timeout.

Non-vsi Session Synchronization: Select this option so that sessions using local interfaces get synchronized among NSRP cluster members. (By default only sessions using virtual security interfaces (VSIs) are synchronized among NSRP cluster members.

Route Synchronization: Select this option to synchronize routes, so the backup device can continue to send traffic when it becomes the primary device and converges with its peers.

Threshold (optional): Enter the time to elapse before the synchronized routes are cleaned on the passive device once it becomes the active. Value is 30-300 seconds.

Click Apply to save your settings.