Solved: restore ios

marcusbrutus · ‎04-09-2008

Hi. If i have accidentally deleted my ios in flash and then after rebooting the router, i am redirected to rommon mode, how do i copy the ios of another router currently attached to the problematic router? Also, what are the steps to be taken should i opt to copy the ios from a tftp server?

Thanks in advance.

Jon Marshall · ‎04-09-2008

No problem with questions.

You can make another router act as the tftp-server if you want. Basically if the tftp server is in a different subnet than the IP address you have assigned in Rommon then you need a default-gateway.

Best thing to do is make sure the tftp-server is in the same subnet so just give your router in Rommon an IP address out of the same subnet as the serial interface on the other router if you want to do it from a router.

Jon

View solution in original post

marcusbrutus · ‎04-09-2008

I was able to find out that after using the set command in rommon mode i should thereafter enter these values:

IP_ADDRESS: 171.68.171.0

IP_SUBNET_MASK: 255.255.254.0

DEFAULT_GATEWAY: 171.68.170.3

TFTP_SERVER: 171.69.1.129

TFTP_FILE: c2600-is-mz.113-

What is the default gateway in this scenario? I mean if the tftp server is directly connected to e0 of my router with an ip of let's say 10.0.1.1/24, should my default gateway be 10.0.1.1?

Jon Marshall · ‎04-09-2008

Apologies, looks like we cross posted.

If tftp server is directly connected then you don't need a default-gateway. But the IP address of the tftp server needs to be in the same subnet as the e0 IP address.

Jon

marcusbrutus · ‎04-09-2008

Thanks Jon for your prompt reply. Just to clarify, are these values correct?

ip_address = 10.0.1.1

subnet_mask = 255.255.255.0

tftp_server = 10.0.1.2

Should i opt to copy the ios from a router, could i just change the ip add of the tftp server to the serial port of the other router where i will be copying the ios from? What should i use as a default router in this scenario. Sorry if i am such a bother.

Jon Marshall · ‎04-09-2008

No problem with questions.

You can make another router act as the tftp-server if you want. Basically if the tftp server is in a different subnet than the IP address you have assigned in Rommon then you need a default-gateway.

Best thing to do is make sure the tftp-server is in the same subnet so just give your router in Rommon an IP address out of the same subnet as the serial interface on the other router if you want to do it from a router.

Jon

Jon Marshall · ‎04-09-2008

Have a look at this document. There are 4 options if you have no valid IOS in flash.

http://www.cisco.com/en/US/products/hw/routers/ps380/products_tech_note09186a008009429e.shtml

Jon