Chassis High Availability Active/Standby Mode

The Chassis High Availability mechanism is based on two identical Chassis. One Chassis handles traffic (Active state), while the other Chassis is in Standby state. The Standby Chassis is synchronized with the Active Chassis so that traffic continues uninterrupted when there is a Chassis failover.

To make sure that the most reliable Chassis is active, each Chassis is assigned a quality grade based on continuous monitoring of its critical components. See set Chassis high-availability factors for a detailed explanation of the grading system.

The Chassis with the highest is automatically selected as the Active Chassis. Whenever the other Chassis grade is greater than the minimum grade gap for failover, failover occurs automatically. See Setting the minimum gap failover for details.

Each Chassis port has its own unique MAC address. The MAC addresses are different for the ports on both Chassis. A Chassis failover event sends GARP packets for each interface. See GARP Chunk Mechanism for details.

You use gclish commands to configure parameters such as:

• Chassis HA grade factors, failover grade difference for failover,
• Failover freeze interval,
• ports factor
• Chassis HA Active Up or Primary Up mode.