Cisco PRP-1= Installation And Configuration Manual page 37

Note
Upgrading the RP ROM Monitor Using Cisco IOS Release 12.0(24)S or Later
Step 1
Step 2
Step 3
Step 4
Step 5
OL-11656-01
The PRP-2 does not require an RP ROM monitor upgrade before Cisco IOS
Software Release 12.0(30)S. If you attempt this upgrade on a PRP-2 using a prior
software release, you will receive the following error message:
Error: Unknown Flash Device type!
GRP ROM monitor upgrade won't continue
New functionality was introduced in Cisco IOS Software Release 12.0(24)S that
enables the secondary RP to have its ROM monitor image upgraded while in
standby mode, and does not require a reboot of the router. In order for this to work,
the router must already be running Cisco IOS Software Release 12.0(24)S or later.
In the following procedure, RP1 is initially the active RP and RP2 is the standby
RP.
After you enter the configuration to load the new Cisco IOS software image,
reload the standby PRP (RP2) using the hw-module standby reload command.
Once the standby RP (RP2) is available again, use the upgrade rom-monitor slot
sec-rp-slot command. If the routine finds that an upgrade is necessary, the new
code will begin to be loaded. When this command is completed, reload the RP2
using the hw-module standby reload command.
Switch over from the active PRP (RP1) to the standby PRP (RP2) using the
redundancy force-switchover command. Once RP2 becomes active, the line
cards will be reloaded.
Let the router return to full operation with Interior Gateway Protocol (IGP) and
Exterior Gateway Protocol (EGP) peers established (this may take a considerable
amount of time, depending on the size and complexity of the router
configuration).
Check the line card CPU utilization using the execute-on all show proc cpu | inc
CPU command. If the CPU utilization has stabilized at the normal running level,
proceed with the next step; otherwise, wait another five minutes and check again.
Performance Route Processor Installation and Configuration Guide
Upgrading to the PRP
37