Cisco Systems Xmodem Transfer Example Using the ROM Monitor, xmodem -c -y -s, 3-12, Command

Chapter 3 Initial Switch Router Configurations

Recovering a System Image Using Xmodem and Ymodem

To copy a Cisco IOS image from a computer or workstation to a router using the Xmodem or Ymodem protocol, use the following commands:

Command	Purpose
xmodem [-c -y -s ]	Copies a system image from a computer to DRAM
	using the ROM monitor.
	The -coption provides CRC-16 checksumming;
	-yuses the Ymodem protocol;
	and -ssets the console port data rate or speed.
	Speeds range from 1200 bps to 57600 bps.

The computer from which you transfer the Cisco IOS image must be running terminal emulation software and the Xmodem or Ymodem protocol.

Xmodem Transfer Example Using the ROM Monitor

This example shows a file transfer using the ROM monitor and the Xmodem protocol. To transmit with the Ymodem protocol, use the xmodem -ycommand.

The Catalyst 2949G-L3 and the Catalyst 4908G-L3 switch routers must have enough DRAM to hold the IOS image file being transferred. The transferred IOS image runs only in DRAM and cannot be stored in boot flash memory. Once your switch router boots up with the transferred image, you can copy a good IOS image from a TFTP server onto the boot flash file system.

Caution A modem connection from the telephone network to your console port introduces security issues that you should consider before enabling the connection. For example, remote users can dial into your modem and access the router’s configuration settings.

To download an IOS image from ROM monitor (using the Xmodem and Ymodem protocols), use the following steps:

Step 1 Place a Cisco IOS software image on the remote computer’s hard drive. You can download an image from Cisco Connection Online.

Step 2 Transfer either from a remote or a local computer.

•To transfer from a remote computer, connect a modem to the console port of your switch router and to the standard telephone network. The modem and console port must communicate at the same speed, which can be from 1200 to 57600 bps, depending on the speed supported by your modem. Use the confreg ROM monitor command to configure the console port transmission speed for the switch router. You can also set the transmission speed with the -soption.

Note We recommend that you use the maximum speed of 57600 bps.The size of an IOS image is approximately 3MB and takes about 10 minutes to transfer at 57600 bps.

Connect a modem to the remote computer and to the telephone network. The remote computer dials through the telephone network and connects to the router.

	Catalyst 2948G-L3 and Catalyst 4908G-L3 Software Feature and Configuration Guide
3-12	78-10408-01, Cisco IOS Release 12.0(7)W5(15d)