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Catalyst 2948G-L3 and Catalyst 4908G-L3 Switch Router Software Feature and Configuration Guide
78-10408-03
Chapter 3 Configurations for the Layer 3 Switch Router
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, perform the following procedure:
The computer from which you transfer the Cisco IOS image must be running terminal emulation
software and the Xmodem or Ymodem protocol.
Example of Xmodem Transfer Using the ROM Monitor Mode
This section explains how to transfer a Cisco IOS image file using the ROM monitor mode and the
Xmodem protocol. You can download an image from Cisco.com.
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 bootflash memory. After your Layer 3 switch router boots up with the transferred image, you can copy
a good IOS image from a TFTP server onto the bootflash file system.
Caution Having 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
in to your modem and access the Layer 3 switch router’s configuration settings.
To download an IOS image from the ROM monitor mode (using the Xmodem and Ymodem protocols),
perform the following steps:
Step 1 Place the Cisco IOS software image on the remote computer’s hard drive.
Step 2 Transfer the image from either a remote or a local computer.
• To transfer the image from a remote computer:
–
Connect a modem to the console port of your Layer 3 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.
Note We recommend that you use the maximum speed of 57600 bps.The size of an IOS image is
approximately 3 MB and takes about 10 minutes to transfer at 57600 bps.
–
Enter the confreg ROM monitor command to configure the console port transmission speed for
the Layer 3 switch router. You can also set the transmission speed with the -s option.
–
Connect a modem to the remote computer and to the telephone network. The remote computer
dials through the telephone network and connects to the Layer 3 switch router.
Task Command
Copy a system image from a computer to DRAM
using the ROM monitor.
The -c option provides cyclic redundancy check
(CRC)-16 checksumming; -y uses the Ymodem
protocol; and -s sets the console port data rate or
speed. Speeds range from 1200 bps to 57600 bps.
xmodem [-c | -y | -s ]