Routing Engine Redundancy on a TX Matrix Platform

On a routing matrix, all master Routing Engines in the TX Matrix platform and connected T640 routing nodes must run the same JUNOS software release. Likewise, all backup Routing Engines in a routing matrix must run the same JUNOS software release. When you run the same JUNOS software release on all master and backup Routing Engines in the routing matrix, a change in mastership to any backup Routing Engine in the routing matrix does not cause a change in mastership in any other chassis in the routing matrix.

If the same JUNOS software release is not running on all master and backup Routing Engines in the routing matrix, the following consequences occur when the failover on-loss-of-keepalives statement is included at the [edit chassis redundancy] hierarchy level:

• When the failover on-loss-of-keepalives statement is included at the [edit chassis redundancy] hierarchy level and you or a host subsystem initiate a change in mastership to the backup Routing Engine in the TX Matrix platform, the master Routing Engines in the T640 routing nodes detect a software release mismatch with the new master Routing Engine in the TX Matrix platform and switch mastership to their backup Routing Engines.
• When you manually change mastership to a backup Routing Engine in a T640 routing node using the request chassis routing-engine master command, the new master Routing Engine in the T640 routing node detects a software release mismatch with the master Routing Engine in the TX Matrix platform and relinquishes mastership to the original master Routing Engine. (Routing Engine mastership in the TX Matrix platform does not switch in this case.)
• When a host subsystem initiates a change in mastership to a backup Routing Engine in a T640 routing node because the master Routing Engine has failed, the T640 routing node is logically disconnected from the TX Matrix platform. To reconnect the T640 routing node, initiate a change in mastership to the backup Routing Engine in the TX Matrix platform, or replace the failed Routing Engine in the T640 routing node and switch mastership to it. The replacement Routing Engine must be running the same software release as the master Routing Engine in the TX Matrix platform.

If the same JUNOS software release is not running on all master and backup Routing Engines in the routing matrix, the following consequences occur when the failover on-loss-of-keepalives statement is not included at the [edit chassis redundancy] hierarchy level:

• If you initiate a change in mastership to the backup Routing Engine in the TX Matrix platform, all T640 routing nodes are logically disconnected from the TX Matrix platform. To reconnect the T640 routing nodes, switch mastership of all master Routing Engines in the T640 routing nodes to their backup Routing Engines.
• If you initiate a change in mastership to a backup Routing Engine in a T640 routing node, the T640 routing node is logically disconnected from the TX Matrix platform. To reconnect the T640 routing node, switch mastership of the new master Routing Engine in the T640 routing node back to the original master Routing Engine.

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