Link to home
Start Free TrialLog in
Avatar of jimburdon
jimburdon

asked on

problem trying to tftpdnld a new router ios to a corrupted router

I have a cisco1721 router. I somehow managed to totally corrupt the ios when loading SDM over the top of the ios. I have since purchased a new ios but cannot figure out how to download this onto the router. Since the ios is corrupted it does not have an ip address and therefore I cannot set the ipaddress variable of the router for tftpdnld command. How do I go about pushing this new ios image on CD down to my router?
Avatar of JFrederick29
JFrederick29
Flag of United States of America image

You'll need to have a TFTP server running on a PC on your network.  You can get a free TFTP server at www.solarwinds.net

Console into the router.  It should be in rommon mode.  If not, you can press CTRL-BREAK within 60 seconds of the router booting to get into rommon mode.

Once in rommon, you need to set the following variables:

IP_ADDRESS—IP address for the router you are using.
IP_SUBNET_MASK—Subnet mask for the router you are using.
DEFAULT_GATEWAY—Default gateway for the router you are using (not required if the TFTP server is in the same subnet as the router).
TFTP_SERVER—IP address of the server from which you want to download the image file.
TFTP_FILE—Name of the file that you want to download.

For example:

rommon 1> IP_ADDRESS=172.15.19.11
rommon 2> IP_SUBNET_MASK=255.255.255.0
rommon 3> DEFAULT_GATEWAY=172.16.19.1
rommon 4> TFTP_SERVER=172.15.20.10
rommon 5> TFTP_FILE=c3620-i-mz.120-4.T

Once you set the above variables, you can type the tftpdnld command and press "y" to proceed:

rommon 6>tftpdnld
Do you wish to continue? y/n: y

Make sure you have your TFTP server running and the previous image in the root of the TFTP server's folder.

Reload the router and it should come up with the new IOS.

http://www.cisco.com/univercd/cc/td/doc/product/access/acs_mod/cis2600/hw_inst/2600hig/2600appb.htm#1042476
Avatar of jimburdon
jimburdon

ASKER

Those were the instructions that I was trying to follow. However, as explained, I don't have the ip address of the router. THe router ios became corrupt, which is why I purcahsed teh new ios. However when you follow through the instructions it tells you to specicy certain variables, the first of which is the ip address of the router!!
What to do?
ASKER CERTIFIED SOLUTION
Avatar of JFrederick29
JFrederick29
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Without the IP address, you need physical access to the box, a rollover cable plugged into the console port, and a laptop.
Set the IP as 10.1.1.1  

In the end it doesn't really matter, you can always change it, but to get your ports working it needs an address.