If you find yourself in ROMMON mode having done something silly like wiping the flash or if there was a problem updating the IOS then the below steps will go though how to copy a replacement image from TFTP to the routers flash.

What you will need

– A tftp server, I tend to use tftpd32
– A compatible IOS image in the base directory of your TFTP server
– The router need a network connection to your TFTP server
– You need to be connected to the router via a console cable

The Commands

Enter the below commands one by one;

IP_ADDRESS=10.0.103.250   (a static IP address for the router)
IP_SUBNET_MASK=255.255.252.0   (the subnet mask for the network the router is plugged into)
DEFAULT_GATEWAY=10.0.100.1   (the default gateway for the network the router is plugged into)
TFTP_SERVER=10.0.101.96   (the ip address of the TFTP server)
TFTP_FILE=c2600-i-mz.123-22.bin   (the full filename of your chosen IOS)
tftpdnld   (This starts the process)

What you should see

 

rommon 14 > tftpdnld

 

IP_ADDRESS: 10.0.103.250 IP_SUBNET_MASK: 255.255.252.0 DEFAULT_GATEWAY: 10.0.100.1 TFTP_SERVER: 10.0.101.96 TFTP_FILE: c2600-i-mz.123-22.bin

Invoke this command for disaster recovery only. WARNING: all existing data in all partitions on flash will be lost! Do you wish to continue? y/n: [n]: y

Receiving c2600-i-mz.123-22.bin from 10.0.101.96 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

File reception completed.

If all goes well type reset to restart the router

Troubleshooting

copy: operation terminated due to bad checksum comparison

If you receive the above message chances are your boot rom is older that 11.3(2)XA4 enter the command TFTP_CHECKSUM=0 and then run tftpdnld again.

This issue is fixed in boot ROM versions 11.3(2)XA4 and later

If all goes well type reset to restart the router