Owner's Manual

Chapter 19. VRRP | 583
NETGEAR 8800 User Manual
management functions, and the backup acts in a standby role. Hitless failover transfers
switch management control from the primary to the backup and maintains the state of VRRP.
VRRP supports hitless failover. You do not explicitly configure hitless failover support; rather,
if you have two nodes installed, hitless failover is available.
Note: For more information about protocol, platform, and support for
hitless failover, see
Understanding Hitless Failover Support on
page 69.
To support hitless failover, the primary node replicates VRRP protocol data units (PDUs) to
the backup, which allows the nodes to run VRRP in parallel. Although both nodes receive
VRRP PDUs, only the primary transmits VRRP PDUs to neighboring switches and
participates in VRRP.
Note: Before initiating failover, review the section Synchronizing Nodes on
Modular Switches on page 825 to confirm that the primary and
backup nodes are running software that supports the synchronize
command.
To initiate hitless failover on a network that uses VRRP:
1. Confirm that the primary and backup nodes are synchronized and have identical
software and switch configurations using the
show switch {detail} command. The
output displays the status of the nodes, with the primary node showing
MASTER and the
backup node showing
BACKUP (InSync).
• If the primary and backup nodes are not synchronized and both nodes are running a
version of XCM8800 that supports synchronization, proceed to
step 2.
• If the primary and backup nodes are synchronized, proceed to step 3.
2. If the primary and backup nodes are not synchronized, use the synchronize command to
replicate all saved images and configurations from the primary to the backup.
After you confirm the primary and backup nodes are synchronized, proceed to step 3.
3. If the primary and backup nodes are synchronized, use the run failover (formerly run
msm-failover)
command to initiate failover.
For more detailed information about verifying the status of the nodes and system
redundancy, see
Understanding System Redundancy on page 64. For more information
about hitless failover, see Understanding Hitless Failover Support on page 69.