Understanding Chassis Cluster

Chassis clustering provides network node redundancy by grouping a pair of the same kind of supported Juniper Networks services routers or services gateways into a cluster. The routers must be running JUNOS software with enhanced services. The two nodes back up each other, with one node acting as the primary and the other as the secondary, ensuring stateful failover of processes and services in the event of system or hardware failure. If the primary node fails, the secondary takes over processing of traffic. Nodes in a cluster are interconnected over Gigabit Ethernet links and synchronize configuration, kernel, and session state across the cluster to facilitate high availability of interfaces and services.

Note: For a services gateway chassis cluster, nodes can also be interconnected over 10 Gigabit Ethernet links.

Note: For a services gateway chassis cluster, nodes must be interconnected with a fiber optic cable.

Chassis cluster functionality includes:

• Resilient system architecture, with a single active control plane for the entire cluster and multiple Packet Forwarding Engines. This presents a single services router or services gateway view of the cluster.
• Synchronization of configuration and dynamic runtime states between nodes within a cluster.
• Monitoring of physical interfaces, and failover if the failure parameters cross a configured threshold.