IOS Image Management CCNA
IOS Image Management CCNA

IOS Image Management

IOS Image Management
5

Summary

This topic implement protocols to manage the network. Start learning CCNA 200-301 for free right now!!

Note: Welcome: This topic is part of Module 10 of the Cisco CCNA 3 course, for a better follow up of the course you can go to the CCNA 3 section to guide you through an order.

Video – Managing Cisco IOS Images

Click Play in the figure to view a demonstration of managing Cisco IOS images.

TFTP Servers as a Backup Location

In the previous topic you learned the ways to copy and paste a configuration. This topic takes that idea one step further with IOS software images. As a network grows, Cisco IOS Software images and configuration files can be stored on a central TFTP server, as shown in the figure. This helps to control the number of IOS images and the revisions to those IOS images, as well as the configuration files that must be maintained.

TFTP Servers as a Backup Location
TFTP Servers as a Backup Location

Production internetworks usually span wide areas and contain multiple routers. For any network, it is good practice to keep a backup copy of the Cisco IOS Software image in case the system image on the router becomes corrupted or accidentally erased.

Widely distributed routers need a source or backup location for Cisco IOS Software images. Using a network TFTP server allows image and configuration uploads and downloads over the network. The network TFTP server can be another router, a workstation, or a host system.

Backup IOS Image to TFTP Server Example

To maintain network operations with minimum down time, it is necessary to have procedures in place for backing up Cisco IOS images. This allows the network administrator to quickly copy an image back to a router in case of a corrupted or erased image.

In the figure, the network administrator wants to create a backup of the current image file on the router (isr4200-universalk9_ias.16.09.04.SPA.bin) to the TFTP server at 172.16.1.100.

Backup IOS Image to TFTP Server Example
Backup IOS Image to TFTP Server Example

Click each button for the steps to create a backup of the Cisco IOS image to a TFTP server.

Ensure that there is access to the network TFTP server. Ping the TFTP server to test connectivity, as shown in the example.

R1# ping 172.16.1.100
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.100, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5),
round-trip min/avg/max = 56/56/56 ms

Verify that the TFTP server has sufficient disk space to accommodate the Cisco IOS Software image. Use the show flash0: command on the router to determine the size of the Cisco IOS image file. The file in the example is 517153193 bytes long.

R1# show flash0: 
-# - --length-- -----date/time------ path
8   517153193   Apr 2 2019 21:29:58  +00:00 
                        isr4200-universalk9_ias.16.09.04.SPA.bin
(output omitted)

Copy the image to the TFTP server by using the copy source-url destination-url command. After issuing the command by using the specified source and destination URLs, the user is prompted for the source file name, IP address of the remote host, and destination file name. Typically, you will press Enter to accept the source filename as the destination file name. The transfer will then begin.

R1# copy flash: tftp: 
Source filename []? isr4200-universalk9_ias.16.09.04.SPA.bin
Address or name of remote host []? 172.16.1.100
Destination filename [isr4200-universalk9_ias.16.09.04.SPA.bin]? 
Writing isr4200-universalk9_ias.16.09.04.SPA.bin...
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 
(output omitted)
517153193 bytes copied in 863.468 secs (269058 bytes/sec)

Copy an IOS Image to a Device Example

Cisco consistently releases new Cisco IOS software versions to resolve caveats and provide new features. This example uses IPv6 for the transfer to show that TFTP can also be used across IPv6 networks.

The figure illustrates copying a Cisco IOS software image from a TFTP server. A new image file (isr4200-universalk9_ias.16.09.04.SPA.bin) will be copied from the TFTP server at 2001:DB8:CAFE:100::99 to the router.

Copy an IOS Image to a Device Example
Copy an IOS Image to a Device Example

Select a Cisco IOS image file that meets the requirements in terms of platform, features, and software. Download the file from cisco.com and transfer it to the TFTP server. Click each button for the steps to upgrade the IOS image on the Cisco router.

Ensure that there is access to the network TFTP server. Ping the TFTP server to test connectivity, as shown in the example.

R1# ping 2001:db8:cafe:100::99
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:CAFE:100::99,
timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), 
round-trip min/avg/max = 56/56/56 ms

Ensure that there is sufficient flash space on the router that is being upgraded. The amount of free flash can be verified by using the show flash: command. Compare the free flash space with the new image file size. The show flash: command in the example is used to verify free flash size. Free flash space in the example is 6294806528 bytes.

R1# show flash: 
-# - --length-- -----date/time------ path
(output omitted)
6294806528 bytes available (537251840 bytes used) 
R1#

Copy the IOS image file from the TFTP server to the router by using the copy command, shown in the example. After issuing this command with specified source and destination URLs, the user will be prompted for the IP address of the remote host, source file name, and destination file name. Typically, you will press Enter to accept the source filename as the destination file name. The transfer of the file will begin.

R1# copy tftp: flash: 
Address or name of remote host []?2001:DB8:CAFE:100::99
Source filename []?  isr4200-universalk9_ias.16.09.04.SPA.bin
Destination filename [isr4200-universalk9_ias.16.09.04.SPA.bin]? 
Accessing tftp://2001:DB8:CAFE:100::99/ isr4200-
universalk9_ias.16.09.04.SPA.bin...
Loading isr4200-universalk9_ias.16.09.04.SPA.bin
from 2001:DB8:CAFE:100::99 (via
GigabitEthernet0/0/0): !!!!!!!!!!!!!!!!!!!!
 
[OK - 517153193 bytes]
517153193 bytes copied in 868.128 secs (265652 bytes/sec)

The boot system Command

To upgrade to the copied IOS image after that image is saved on the flash memory of the router, configure the router to load the new image during bootup by using the boot system command, as shown in the example. Save the configuration. Reload the router to boot the router with new image. At the [confirm] prompt, press Enter to continue. Otherwise press Control-C to cancel.

R1# configure terminal
R1(config)# boot system flash0:isr4200-universalk9_ias.16.09.04.SPA.bin
R1(config)# exit
R1#
R1# copy running-config startup-config
R1#
R1# reload
Proceed with reload? [confirm] 

*Mar  1 12:46:23.808: %SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload Command.

During startup, the bootstrap code parses the startup configuration file in NVRAM for the boot system commands that specify the name and location of the Cisco IOS Software image to load. Several boot system commands can be entered in sequence to provide a fault-tolerant boot plan.

If there are no boot system commands in the configuration, the router defaults to loading the first valid Cisco IOS image in flash memory and runs it.

After the router has booted, to verify that the new image has loaded, use the show version command, as displayed in the example.

R1# show version
Cisco IOS XE Software, Version 16.09.04
Cisco IOS Software [Fuji], ISR Software (X86_64_LINUX_IOSD-UNIVERSALK9_IAS-M), Version 16.9.4, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2019 by Cisco Systems, Inc.
Compiled Thu 22-Aug-19 18:09 by mcpre
Cisco IOS-XE software, Copyright (c) 2005-2019 by cisco Systems, Inc.
All rights reserved.  Certain components of Cisco IOS-XE software are
licensed under the GNU General Public License ("GPL") Version 2.0.  The
software code licensed under GPL Version 2.0 is free software that comes
with ABSOLUTELY NO WARRANTY.  You can redistribute and/or modify such
GPL code under the terms of GPL Version 2.0.  For more details, see the
documentation or "License Notice" file accompanying the IOS-XE software,
or the applicable URL provided on the flyer accompanying the IOS-XE
software.
   
ROM: IOS-XE ROMMON
Router uptime is 2 hours, 19 minutes
Uptime for this control processor is 2 hours, 22 minutes
System returned to ROM by PowerOn
System image file is "flash:isr4200-universalk9_ias.16.09.04.SPA.bin"
(output omitted)

Packet Tracer – Use a TFTP Server to Upgrade a Cisco IOS Image

A TFTP server can help manage the storage of IOS images and revisions to IOS images. For any network, it is good practice to keep a backup copy of the Cisco IOS Software image in case the system image in the router becomes corrupted or accidentally erased. A TFTP server can also be used to store new upgrades to the IOS and then deployed throughout the network where it is needed. In this activity, you will upgrade the IOS images on Cisco devices by using a TFTP server. You will also backup an IOS image with the use of a TFTP server.

Glossary: If you have doubts about any special term, you can consult this computer network dictionary.

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