Configuring Switching Control Board Redundancy

The Compact Forwarding Engine Board (CFEB) on the M10i router provides route lookup, filtering, and switching on incoming data packets, and then directs outbound packets to the appropriate interface for transmission to the network. The CFEB communicates with the Routing Engine using a dedicated 100-Mbps Fast Ethernet link that transfers routing table data from the Routing Engine to the forwarding table in the integrated ASIC. The link is also used to transfer from the CFEB to the Routing Engine routing link-state updates and other packets destined for the router that have been received through the router interfaces.

To configure a CFEB redundancy group, include the following statements at the [edit chassis redundancy] hierarchy level:

slot-number can be 0 or 1.

always defines the CFEB as the sole device.

preferred defines a preferred CFEB.

To manually switch CFEB primary role, issue the request chassis cfeb master switch command. To view CFEB status, issue the show chassis cfeb command.

To configure a FEB redundancy group for the M120 router, include the following statements at the [edit chassis redundancy feb] hierarchy level:

group-name is the unique name for the redundancy group. The maximum length is 39 alphanumeric characters.

slot-number is the slot number of each FEB you want to include in the redundancy group. The range is from 0 through 5. You must specify exactly one FEB as a backup FEB per redundancy group. Include the backup keyword when configuring the backup FEB and make sure that the FEB is not connected to an FPC.

Include the primary keyword to optionally specify one primary FEB per redundancy group. When the primary keyword is specified for a particular FEB, that FEB is configured for 1:1 redundancy. With 1:1 redundancy, the backup FEB contains the same forwarding state as the primary FEB. When no FEB in the redundancy group is configured as a primary FEB, the redundancy group is configured for n:1 redundancy. In this case, the backup FEB has no forwarding state. When a FEB fails, the forwarding state must be downloaded from the Routing Engine to the backup FEB before forwarding continues.

A combination of 1:1 and n:1 redundancy is possible when more than two FEBs are present in a group. The backup FEB contains the same forwarding state as the primary FEB, so that when the primary FEB fails, 1:1 failover is in effect. When a nonprimary FEB fails, the backup FEB must be rebooted so that the forwarding state from the nonprimary FEB is installed on the backup FEB before it can continue forwarding.

You can optionally include the description statement to describe a redundancy group.

Automatic failover is enabled by default. To disable automatic failover, include the no-auto-failover statement. If you disable automatic failover, you can perform only a manual switchover using the operational command request chassis redundancy feb slot slot-number switch-to-backup.

To view FEB status, issue the show chassis feb command. For more information, see the CLI Explorer.

By default, the Switching and Forwarding Module (SFM) in slot 0 is the primary and the SFM in slot 1 is the backup. To modify the default configuration, include the sfm statement at the [edit chassis redundancy] hierarchy level:

On the M40e router, slot-number is 0 or 1. On the M160 router, slot-number is 0 through 3.

always defines the SFM as the sole device.

preferred defines a preferred SFM.

To manually switch primary role between SFMs, issue the request chassis sfm master switch command. To view SFM status, issue the show chassis sfm command. For more information, see the CLI Explorer.

For M20 routers with two System and Switch Boards (SSBs), you can configure which SSB is the primary and which is the backup. By default, the SSB in slot 0 is the primary and the SSB in slot 1 is the backup. To modify the default configuration, include the ssb statement at the [edit chassis redundancy] hierarchy level:

slot-number is 0 or 1.

always defines the SSB as the sole device.

preferred defines a preferred SSB.

To manually switch primary role between SSBs, issue the request chassis ssb master switch command.

To display SSB status information, issue the show chassis ssb command. The command output displays the number of times the primary role has changed, the SSB slot number, and the current state of the SSB: primary, backup, or empty. For more information, see the CLI Explorer.

For routers that have multiple Routing Engines or these multiple switching control boards: Switching and Forwarding Modules (SFMs), System and Switch Boards (SSBs), Forwarding Engine Boards (FEBs), or Compact Forwarding Engine Boards (CFEBs), you can configure redundancy properties.

To configure redundancy, include the following redundancy statements at the [edit chassis] hierarchy level: