M20 Router Routing Engine Redundancy
The M20 router has one Routing Engine in slot RE0 and another in slot RE1 (see Figure 194). By default, the Routing Engine in slot RE0 is the master and the one in slot RE1 is the backup. If one Routing Engine fails, the other one assumes the routing functions.
The M20 router Routing Engine panel has LEDs that indicate redundant Routing Engine operating status and mastership. The craft interface also has LEDs that indicate redundant Routing Engine status and mastership. (See Check the M20 Router Routing Engine LEDs.)
