Bringing a SUP720 back to its default configuration is fairly simple but there are a few key differences in comparison to other Cisco products. The SUP720 has 2 different processors, a switch processor and a route processor that both perform different functions. The switch proceesor, or SP, runs on Cisco's CatOS while the route processor, or RP, runs its own native IOS (the type of OS that we are most used to seeing on Cisco units). To correctly reset a SUP720 to its default parameters, you must understand this function and know when to press the break sequence, otherwise the configuration registers of both the SP and RP won't sync up. If the config registers are off then the unit will not boot, displaying software forced reloads until the problem is corrected. IF YOU ARE ONLY WANTING TO RECOVER THE PASSWORD WITHOUT DESTROYING YOUR STARTUP CONFIG, HAVE A BACKUP MADE BEFORE HAND IF POSSIBLE OR COPY THE ENTIRE CONFIGURATION AS NOTED IN STEP 5.
1. Power cycle the SUP720
2. On the Catalyst 6500/SUP720 that runs Cisco IOS, the SP will boot first and will then switch ownership to the RP. When the RP gains control you will see a message that looks like this:
00:00:03: %OIR-6-CONSOLE: Changing console ownership to route processor
After you see this message, press Ctrl+BREAK until you see the rommon> prompt. The break sequence will put you into the RP's ROM monitor or ROMMON.
3. Type confreg 0x2142 at the > prompt to boot from flash while ignoring the startup configuration. Press Enter and then type Reset and press enter again.
4. The RP will then reload into the new configuration register. Answer no to the setup up questions and then type en or enable at the Router prompt. Press enter and you will be in enable mode, the prompt will look like this Router#.
5. Type in the sh config command. This will show you the current startup configuration file. NOTE: IF YOU ARE ONLY TRYING TO RECOVER A PASSWORD, MAKE SURE AND CAPTURE YOUR ENTIRE CONFIGURATION FOR FUTURE USE IF YOU DON'T ALREADY HAVE ONE. You will see a line that begins with boot system followed by disk0:, disk1:, or bootflash: and the file name of the IOS that the RP is running. Copy this entire line to your terminal, it will look something like this: boot system disk0:yourimagefilename.bin.
6.Hit the Spacebar or any other key to return to the Router# prompt. Use the sh run command to see your running configuration. Check to make sure that there is in fact no boot system line. Return to the Router# prompt and type in erase start to delete the entire startup configuration. This will clear the contents of NVRAM, as I said before, if you need this information make a backup copy beforehand.
7. Now that the startup config is cleared, you can enter into global configuration mode by typing config t and pressing enter. This will allow you to change the SUP720's running configuration, which is its 'default' config. Now type or paste the boot system line from step 5 and press enter. Also, while you're here, go ahead and type config 0x2102 and press enter. Press Ctrl+Z to exit global configuration mode, this automatically saves your work to the running config.
8. Now that your boot variable and config register have been written to the running config, enter a copy run start and press enter to copy your new base running config into the NVRAM or startup config.
9. Before reloading, enter the sh bootvar to check the configuration register for the RP and the remote command switch sh bootvar for the SP. The bottom line of the RP's readout should say config register 0x2142(will be 0x2102 at next reload), while the SP's should just say config register 0x2102. Confirm that both of these are correct and then issue the reload command and press enter. If the configuration registers are set to sync at the next reload, you may encounter startup problems or the router may crash completely. After reload, the SUP720 should boot up normally with no passwords and a completely clear 'default' configuration. You will now be able to reconfigure the unit as you see fit.