User Reference Manual.book

Control Modules
Control Modules
Introduction
The Control Module functions as the brain of the router. The XP-8000/8600 and ER16 can support
up to two control modules (the primary and backup CMs), residing in slots 0 and 1 on the
XP-8000/8600 and slots 8 and 9 on the ER16. The Primary CM is the CM in control of the router
and processes packets that come through it. The backup CM remains in standby mode, receiving
heartbeats from the Primary CM.
Although the backup CM is on standby, it has its PCMCIA card mounted and has booted its
firmware image. The backup CM is not aware of the line cards installed in the X-Pedition and has
not processed the startup configuration—both of these operations must be performed in order for
the backup CM to assume control of the X-Pedition (i.e., a system fail-over). The time required for
the X-Pedition to switch control to the backup CM depends on the number of line cards installed
and the length of the configuration file.
Note: In a dual Control Module configuration, both modules must be of the same type (CM2,
CM3, or CM4), share the same Boot Firmware version, and should use the same size and
type of memory.
The procedure for hot swapping a Control Module is similar to the procedure for hot swapping a
line card. You must deactivate the Control Module, remove it from the X-Pedition, and insert
another Control Module in the slot. If dual CMs are installed on the X-Pedition, you can hot swap
the Backup CM it with another Control Module.
Single CM Environments
The X-Pedition does not support hot swapping a Control Module in a single CM environment. To
replace a Control Module in this environment, do the following:
WARNING The X-Pedition and its components are sensitive to static discharge. To prevent
electrostatic damage, observe the guidelines provided in Preventing Electrostatic
Damage on page 17.
1. Power down the router and make sure that none of the LEDs on the Control Module are lit.
2. Loosen the captive screws on each side of the Control Module and, in the case of the ER16,
open the ejectors.
3. Carefully remove the Control Module from its slot in the chassis.
4. Slide the new Control Module all the way into the slot reserved for the Primary control
module, firmly but gently pressing it in place to ensure that the pins on the back of the card are
completely seated in the backplane. Make sure the circuit card (and not the metal plate) is
between the card guides. Check both the upper and lower tracks.
20 Enterasys X-Pedition User Reference Manual