Cisco IOS – upgrade after failed boot

Cisco IOS – upgrade after failed bootHow to revive a Cisco router after unsuccessful IOS upgrade

Just a reminder for myself. As recently I started attending Network Infrastructure course I am spending more and more time with Cisco equipment. The last couple of days proved to be a bit troublesome (not to mention bad luck with ebay shopping – damaged wic-1enet & vic-2fxs that turned out to be 2x wic-1t – damn you ebay!). It seems that something goes wrong every other day! Good job I am patient I suppose. Next time one of your routers start crashing on boot after IOS upgrade it can be revived using following commands:

rommon 1 >IP_ADDRESS=
rommon 2 >IP_SUBNET_MASK=
rommon 4 >TFTP_SERVER=
rommon 5 >TFTP_FILE=c2600-adventerprisek9-mz.124-17.bin
rommon 6 >tftpdnld

Might need to press Y to continue. Once new IOS is downloaded and installed on flash: you might need to type “i”, hit enter and your new IOS will hopefully boot. Joy!