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Catalyst 2948G-L3 and Catalyst 4908G-L3 Software Feature and Configuration Guide
78-10408-01, Cisco IOS Release 12.0(7)W5(15d)
Chapter 3 Initial Switch Router Configurations
Recovering a System Image Using Xmodem and Ymodem
Recovering a System Image Using Xmodem and Ymodem
If you do not have access to a network server and need to download a system image, you can copy an
image from a local or remote computer (such as a PC, UNIX workstation, or Macintosh computer) using
the Xmodem or Ymodem protocols. This functionality primarily serves as a disaster recovery
technique. See Figure 3-1.
Xmodem and Ymodem are common protocols used for transferring files and are included in
applications such as Windows 3.1 (TERMINAL.EXE), Windows 95 (HyperTerminal), Windows NT
3.5x (TERMINAL.EXE), Windows NT 4.0 (HyperTerminal), and Linux UNIX freeware (minicom).
Xmodem and Ymodem downloads are slow, so you should use them only when you do not have access
to a network server. You can speed up the transfer by setting the transfer port speed to 57600 bps.
If all local system images are damaged or erased on your switch router, you can perform the file transfer
by using the ROM monitor. On the Catalyst 2948G-L3 and the Catalyst 4908G-L3, you can only
perform the file transfer from the ROM monitor over the console port.
Note Perform file transfer from the ROM monitor with either Cisco IOS Release
12.0(7)W5(15a) or later. To verify the ROM monitor version, use either the show version
command from Cisco IOS software or issue the reset command from ROM MON mode.
Figure 3-1 shows file transfer using the Xmodem or Ymodem protocols. The connection is from either
a local or a remote computer to your switch router. You can make the connection using either the COM
port on the local computer or using a modem with the remote computer.
Figure 3-1 Transferring a System Image to a Layer 3 Switch Router Using Xmodem and Ymodem
Protocols
Catalyst 2948G-L3 or
Catalyst 4908G-L3 switch
router downloading a
Cisco IOS software image
from a local or remote PC
38417
Telephone
network
Remote PC
running terminal
emulation software
and Xmodem and
Ymodem protocols
Modem
Modem
Console
port
Local PC running
terminal emulation
software and Xmodem
and Ymodem protocols
