Replacing an SSB

One or two SSBs can be installed into the uppermost slots in the front of the chassis, as shown in Figure 1. Only one SSB is active at a time, with the optional second SSB in reset mode. SSBs are hot-pluggable, as described in Field-Replaceable Units (FRUs). Removing the standby SSB has no effect on router function. If the active SSB fails or is removed from the chassis, the effect depends on whether two SSBs are installed:

• If there is only one SSB, forwarding halts until the SSB is replaced and functioning again.
• If there are two SSBs, forwarding halts until the standby SSB boots and becomes active.

In both cases, all components in the Packet Forwarding Engine reset, and it takes approximately one minute for the new SSB to become active; synchronizing router configuration information can take additional time, depending on the complexity of the configuration.

To replace an SSB, perform the following procedures:

• Removing an SSB
• Installing an SSB