Maintaining the M120 FEBs
Purpose
For optimum cooling, verify the condition of the FEBs.
Action
On a regular basis:
- Check the LEDs on the FEB faceplate. For more information on the FEB LEDs, see FEB LEDs.
- Check the FEB LEDs on the craft interface to view information; see FEB LEDs on the Craft Interface.
- Issue the CLI show chassis feb command to check
the status of each of the installed FEBs. As shown in the sample output,
the value Online in the column labeled State indicates
that the FEB is functioning normally.
user@host> show chassis febTemp CPU Utilization (%) Memory Utilization (%) Slot State (C) Total Interrupt DRAM (MB) Heap Buffer 0 Empty 1 Empty 2 Online 44 4 0 512 7 63 3 Online 46 4 0 512 7 63 4 Online 45 3 0 512 7 63 5 Online 42 4 0 512 7 63
For more detailed output, add the detail option. The following example also specifies a slot number (0), which is optional:
user@host> show chassis feb detail 0Slot 0 information: State Online Intake temperature 66 degrees C / 150 degrees F Exhaust A temperature 67 degrees C / 152 degrees F Exhaust B temperature 73 degrees C / 163 degrees F Total DDR DRAM 512 MB Total RLDRAM 64 MB Start time: 2006-09-08 16:29:59 PDT Uptime: 1 hour, 3 minutes, 4 seconds
You can also issue the show chassis environment feb command to check the status of a specific FEB. In the example below, the FEB is slot 0 is used. The output is similar to the following:
user@host> show chassis environment feb 0FEB 0 status: State Online Temperature Intake 66 degrees C / 150 degrees F Temperature Exhaust A 67 degrees C / 152 degrees F Temperature Exhaust B 73 degrees C / 163 degrees F Power 1.2 V 1153 mV 1.5 V 1417 mV 1.8 V 1704 mV 2.5 V 2375 mV 3.3 V 3138 mV 5.0 V 4763 mV 1.2 V Rocket IO 1160 mV 1.5 V Rocket IO 1408 mV 1.8 V RLDRAM 1717 mV I2C Slave Revision 15 - To take a FEB offline or online or restart it, click Offline, Online, enter the request chassis feb
(online | offline | restart) slot slot-number command.

Note: If you bring a FEB offline (or remove it), interfaces on FPCs connected to the FEB are deleted. When you bring the FEB back online, the interfaces are restored.
- Plan FEB redundancy groups according to your network requirements.
A FEB redundancy group is a named collection of two or more Forwarding Engine Boards (FEBs) that can improve interface availability. You can design your redundant FEB configuration to provide backup on a one-to-one basis, or you can provide one backup for multiple FEBs. Each FEB redundancy group can contain only one primary FEB.
To create or edit FEB redundancy groups, use the edit chassis redundancy feb-redundancy group group-name command.
- Change the default assignments of FPCs to FEBs according
to your network requirements. By default, each FPC is assigned to
the FEB of the same identifying number; for example, FPC 1 is
assigned to FEB 1.
- To assign an FPC to a FEB, use the fpc-feb-connectivity statement at the [edit chassis] hierarchy level. You can also map an FPC to none to specify that the FPC is not mapped to any FEB. (When an FPC is configured not to connect to any FEB, interfaces on that FPC are not created; however, no alarm is triggered.)
- To view which FPCs are mapped to which FEBs and the status of each link, enter the show chassis fpc-feb-connectivity command.
For more information about FEB redundancy groups and FPC-to-FEB connectivity, see the Junos System Basics Configuration Guide.
