In the recent years there have been a number of control boards. There are a number of challenges that one experiences on a control board which include backing up data. This failure occurs when the hardware fails to backup data. One can also manually backup data on the switch board but this takes time. Below we discuss more about it.

Route lookups—this happens when it forwards table stored in synchronous (SSRAM).

Manages memory—It manages data that will be coming from the switchboard.

Controls outgoing data—this is whereby the interface transfers data to the fixed interface card when the data has been transmitted.

The M120 router

 M120 router allows up to six Forwarding Engine Boards. PIC Concentrator (FPCs), which host PICs, are separate from the FEBs, which handle packet forwarding. FPCs are located on the front of the chassis and provide power and management to PICs through the mid plane. 

FEBs are located on the back of the chassis and receive signals from the mid plane, which the FEBs process for packet forwarding. The mid plane allows any FEB to carry traffic for any FPC.


When you configure a primary FEB in a redundancy group, the backup FEB mirrors the exact forwarding state of the primary FEB. If switchover occurs from a primary FEB, the backup FEB does not reboot. A manual switchover from the primary FEB to the backup FEB results in less than 1 second of traffic loss. Failover from the primary FEB to the backup FEB results in less than 10 seconds of traffic loss.


If a failover occurs from the other FEB and a primary FEB is specified for the group, the backup FEB reboots so that the forwarding state from the other FEB can be downloaded to the backup FEB and forwarding can continue. Automatic failover from a FEB that is not specified as a primary FEB results in higher packet loss. The duration of packet loss depends on the number of interfaces and on the size of the routing table, but it can be minutes.


If a fail over from a FEB occurs when no primary FEB is specified in the redundancy group, the backup FEB does not reboot and the interfaces on the FPC connected to the previously active FEB remain online. The backup FEB must obtain the entire forwarding state from the 

When one fails to backup FBE the data will become automatically erased which is a major setback.

Route lookups—The SSB performs route backups using the SSRAM. After the backup, the Internet Processor then sends a signal to the mid plane about the backup then it finally processes it.


M20 router holds up to two SSBs. The first SSB saves data automatically while the second SSB is the backup. It is possible for one to do a manual switchover.

In summation, when performing a router backup many soft wares’ are involved in the process and therefore one has to be careful when using routers on a switchboard.