Radio Shack FC-241 User Manual
Configuring Additional File Transfer Functions
This chapter describes how to configure a router as a server, change MOP parameters, configure the
router to forward extended BOOTP requests over asynchronous interfaces, and configure rcp, rsh, and
FTP.
For a complete description of the file transfer function commands mentioned in this chapter, refer to the
“Additional File Transfer Functions Commands” chapter in the Configuration Fundamentals Command
Reference. To locate documentation of other commands that appear in this chapter, use the command
reference master index or search online.
Additional Functions Task List
To configure additional file transfer functions, perform any of the tasks in the following sections:
• Configuring a Router as a Server
• Specifying Asynchronous Interface Extended BOOTP Requests
• Configuring a Router to Use rsh and rcp
• Configuring a Router to Use FTP Connections
Configuring a Router as a Server
It is too costly and inefficient to have a machine which only acts as server on every network segment.
However, when you do not have a server on every segment, your network operations can incur enormous
time delays across network segments. You can configure a router to serve as a RARP or TFTP server to
reduce costs and time delays in your network while allowing you to use your router for its regular
functions.
Typically, a router that is configured as a server provides other routers with operating system images
from its Flash memory. You can also configure the router to respond to other types of service requests,
such as Reverse Address Resolution Protocol (RARP) requests.
To configure the router as a server, perform any of the tasks in the following sections. The tasks are not
mutually exclusive.
• Configuring a Router as a TFTP Server
• Configuring a Router as a RARP Server
First Published: July 14, 2000; Last Updated: Oct. 1, 2002
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Configuring a Router as a Server
In addition, you can configure the Cisco IOS software to forward extended BOOTP requests over
asynchronous interfaces. Refer to the “Configuring SLIP and PPP” chapter of the Dial Solutions
Configuration Guide for more information.
Configuring a Router as a TFTP Server
As a TFTP server host, the router responds to TFTP Read Request messages by sending a copy of the
system image contained in ROM or one of the system images contained in Flash memory to the
requesting host. The TFTP Read Request message must use one of the filenames that are specified in the
configuration.
Note For the Cisco 7000 family, the filename used must represent a software image that is
present in Flash memory. If no image resides in Flash memory, the client router will boot
the server’s ROM image as a default.
Flash memory can be used as a TFTP file server for other routers on the network. This feature allows
you to boot a remote router with an image that resides in the Flash server memory.
With Cisco IOS Release 11.0, Cisco 7000 family allow you to specify one of the different Flash memory
devices (bootflash:, slot0:, slot1:, slavebootflash:, slaveslot0:, or slaveslot1:) as the TFTP server.
In the description that follows, one Cisco 7000 router is referred to as the Flash server, and all other
routers are referred to as client routers. Example configurations for the Flash server and client routers
include commands as necessary.
Configuring Additional File Transfer Functions
To configure a router as a TFTP server, perform the tasks in the following sections:
• Performing Prerequisite Tasks
• Configuring the Server
• Configuring the Client Router
Performing Prerequisite Tasks
The server and client router must be able to reach each other before the TFTP function can be
implemented. Verify this connection by pinging between the server and client router (in either direction)
with the ping command.
An example use of the ping command is as follows:
Router# ping 172.16.101.101
In this example, the Internet Protocol (IP) address of 172.16.101.101 belongs to the client router.
Connectivity is indicated by a series of exclamation points (!), while a series of periods (.) plus [timed
out] or [failed] indicates no connection. If the connection fails, reconfigure the interface, check the
physical connection between the Flash server and client router, and ping again.
After you verify the connection, ensure that a TFTP-bootable image is present on the server. This is the
system software image the client router will boot. Note the name of this software image so you can verify
it after the first client boot.
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Caution For full functionality, the software image sent to the client must be the same type as the
ROM software installed on the client router. For example, if the server has X.25 software,
and the client does not have X.25 software in ROM, the client will not have X.25
capabilities after booting from the server’s image in Flash memory.
Configuring the Server
To specify TFTP server operation, use the following commands in configuration mode:
Command Purpose
Step 1
Step 2
configure terminal
tftp-server flash [partition-number:]filename1
[alias filename2] [access-list-number]
or
tftp-server flash device:filename (Cisco 7000 family
only)
Configuring a Router as a Server
Enters global configuration mode from the terminal.
Specifies the system image to send in response to
Read Requests. You can enter multiple lines to
specify multiple images.
Step 3
Step 4
or
tftp-server flash
[device:][partition-number:]filename
(Cisco 1600 series and Cisco 3600 series only)
or
tftp-server rom alias filename1 [access-list-number]
end
copy running-config startup-config
The TFTP session can sometimes fail. TFTP generates the following special characters to help you
determine why a TFTP session fails:
• An “E” character indicates that the TFTP server received an erroneous packet.
• An “O” character indicates that the TFTP server received an out-of-sequence packet.
• A period (.) indicates a timeout.
For diagnosing any undue delay in the transfer, the output is useful. For troubleshooting procedures,
refer to the Internetwork Troubleshooting Guide publication.
In the following example, the system can use TFTP to send copies of the Flash memory file version-10.3
in response to a TFTP Read Request for that file. The requesting host is checked against access list 22.
tftp-server flash version-10.3 22
Exits configuration mode.
Saves the configuration file to your startup
configuration.
In the following example, the system can use TFTP to send a copy of the ROM image gs3-k.101 in
response to a TFTP Read Request for the gs3-k.101 file:
tftp-server rom alias gs3-k.101
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The following example a router to send a copy of the file gs7-k.9.17 in Flash memory in response to a
TFTP Read Request. The client router must reside on a network specified by access list 1. Thus, in the
example, the any clients on network 172.16.101.0 are permitted access to the file.
Server# configure terminal
Enter configuration commands, one per line. End with CTRL/Z
Server(config)# tftp-server flash gs7-k.9.17 1
Server(config)# access-list 1 permit 172.16.101.0 0.0.0.255
Server(config)# end
Server# copy running-config startup-config
[ok]
Server#
Configuring the Client Router
Configure the client router to first load a system image from the server. As a backup, configure the client
router to then load its own ROM image if the load from a server fails. To configure the client router, use
the following commands beginning in privileged EXEC mode:
Command Purpose
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Step 7
Step 8
Step 9
Step 10
configure terminal
no boot system
boot system [tftp] filename [ip-address]
boot system rom
config-register value
end
copy running-config startup-config
reload
show version
Configuring Additional File Transfer Functions
Enters global configuration mode from the terminal.
Removes all previous boot system statements from
the configuration file.
Specifies that the client router load a system image
from the server.
Specifies that the client router loads its own ROM
image if the load from a server fails.
Sets the configuration register to enable the client
router to load a system image from a network server.
Exits global configuration mode.
Saves the configuration file to your startup
configuration.
Reloads the router to make your changes take effect.
(Router reboots.)
Verifies that the client router booted the correct image
from the TFTP server.
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Caution Using the no boot system command, as in the following example, will invalidate all other
boot system commands currently in the client router system configuration. Before
proceeding, determine whether the system configuration stored in the client router should
first be saved (uploaded) to a TFTP file server so you have a backup copy.
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The following example shows how to configure a router to use a TFTP server:
Client# configure terminal
Enter configuration commands, one per line. End with CTRL/Z
Client(config)# no boot system
Client(config)# boot system gs7-k.9.17 172.31.111.111
Client(config)# boot system rom
Client(config)# config-register 0x010F
Client(config)# end
Client# copy running-config startup-config
[ok]
Client# reload
In this example, the no boot system command invalidates all other boot system commands currently in
the configuration memory, and any boot system commands entered after this command will be executed
first. The second command, boot system filename address, tells the client router to look for the file
gs7-k.9.17 on the TFTP server with an IP address of 172.31.111.111. Failing this, the client router will
boot from its system ROM in response to the boot system rom command, which is included as a backup
in case of a network problem. The copy running-config startup-config command copies the
configuration to the startup configuration, and the reload command boots the system.
Configuring a Router as a Server
Caution The system software (gs7-k.9.17 in the example) to be booted from the server
(172.31.111.111 in the example) must reside in Flash memory on the server. If it is not in
Flash memory, the client router will boot the server’s system ROM.
The following example shows sample output of the show version command after the router has rebooted:
Client> show version
GS Software (GS7), Version 9.1.17
Copyright (c) 1986-1992 by cisco Systems, Inc.
Compiled Wed 21-Oct-92 22:49
System Bootstrap, Version 4.6(0.15)
Current date and time is Thu 10-22-1992 13:15:03
Boot date and time is Thu 10-22-1992 13:06:55
env-chassis uptime is 9 minutes
System restarted by power-on
System image file is “gs7-k.9.17”, booted via tftp from 172.31.111.111
RP1 (68040) processor with 16384K bytes of memory.
X.25 software.
Bridging software.
1 Switch Processor.
1 EIP controller (6 Ethernet).
6 Ethernet/IEEE 802.3 interface.
128K bytes of non-volatile configuration memory.
4096K bytes of flash memory on embedded flash (in RP1).
Configuration register is 0x010F
The important information in this example is contained in the first line “GS Software...” and in the line
that begins “System image file....” The “GS Software...” line shows the version of the operating system
in the client router’s RAM. The “System image file....” line show the filename of the system image
loaded from the TFTP server.
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