Explanation
A chassis cluster is a pair of SRX Series devices that are connected and configured to operate as a single node, providing high availability and load balancing for traffic flows1. A chassis cluster consists of two nodes:
one primary and one secondary. Each node can host one or more redundancy groups, which are logical entities that group the interfaces and services that need to fail over together in case of a node failure2. Redundancy group 0 is a special group that monitors the control plane of the cluster, such as the routing engine and the control link. Redundancy group 0 is always active on the primary node and standby on the secondary node3.
Therefore, option A is false. Each chassis cluster member requires a unique node ID value, which can be either
0 or 1, to identify itself within the cluster4. However, the cluster ID value is the same for both nodes, and it is used to identify the cluster as a whole. Therefore, option B is false. Each chassis cluster member device can host active redundancy groups, depending on the configuration and the status of the nodes. By default, the primary node hosts all the redundancy groups, but you can configure some groups to be preempted by the secondary node if it has a higher priority or load-sharing between the nodes if they have the same priority.
Therefore, option C is true. Chassis cluster member devices must be the same model, because different models have different hardware and software specifications that may not be compatible with each other in a cluster.
Therefore, option D is true. References:
Chassis Cluster User Guide for SRX Series Devices
Understanding Chassis Cluster Redundancy Groups
Understanding Redundancy Group 0
Understanding Chassis Cluster Node IDs
[Understanding Chassis Cluster Cluster IDs]
[Configuring Chassis Cluster Redundancy Group Settings]
[Chassis Cluster Feature Guide for SRX Series Devices]