Downloading the software

As you know, you have to have a Cisco maintenance agreement as well as an online account linked to that agreement so you can legally download the new IOS. So assuming you meet that criteria and have already downloaded your desired IOS, let’s get started on the upgrade process. If you haven’t downloaded the IOS yet, you can do so at http://support.cisco.com

Prepare for disaster

Ok, maybe that title was a little strong. But you need to backup your existing IOS image as well as your current configuration. If something goes wrong during the upgrade, you’ll want to bring things back as quickly as possible.

• So first, let’s run the TFTP server software. I’m using Tftpd32 available for free at http://tftpd32.jounin.net
• Now from the switch CLI determine your current IOS version by typing:

Router# show version

On my switch the version, as mentioned before, is 12.2(25) SEE3.

• Now locate the current IOS image using the dir command as shown:

Router# dir

From here I can see a directory named c3560-ipbasek9-mz.122-25.SEE3 which matches my version number above. Obviously depending on the version of IOS you’re running, this directory name will be different.

• So we now see the directory that contains the current IOS. Change to that directory and issue the dir command again to view the image file name.

Router# cd c3560-ipbasek9-mz.122-25.SEE3

Router# dir

• I can now see the image file c3560-ipbasek9-mz.122-25.SEE3.bin and that’s the file that we want to backup. So with our TFTP program running we have what we need to back up the current IOS. From the switch CLI type the following to start the IOS backup:

Router# copy flash:c3560-ipbasek9-mz.122-25.SEE3.bin tftp

Address or name of remote host []? 192.168.28.1

Destination filename [c3560-ipbasek9-mz.122-25.SEE3.bin]?

The remote host IP address is the IP displayed in the Server Interface field of the Tftpd32 program. After a little time, the download will finish and you should see a copy of the IOS in the directory shown in the Current Directory field of Tftpd32 as shown in Figure A.

Figure A: You’ll need TFTP software to be able to upgrade and backup your switch.

• Next you need to back up your current configuration as follows:

Router# cd ..

Router# copy flash:config.text tftp

Address or name of remote host []? 192.168.28.1

Destination filename [config.txt]?

Upgrading the switch

So now that we have a good copy of both the current IOS and configuration, we’re ready to upload the new image. I’ve downloaded the tar package named c3560-ipbasek9-tar.122-44.SE6.tar form Cisco and placed it in my Tftpd32 Current Directory location. Also, on my switch I have enough room in flash to leave the current IOS and still be able to upload the newer image. This allows me to specify which image to boot from and test the upgrade before actually removing the older version. If you have the space, I suggest you do the same. It’s just another safety net in case something goes awry. If you don’t have the space, then you’ll have to delete the existing image first before performing the upgrade.

• To start the upgrade, from the switch CLI type the following:

Router# archive tar /xtract tftp://192.168.28.1/c3560-ipbasek9-tar.122-44.SE6.tar flash:

After a few minutes the tar file will complete the upload and extraction and you’ll receive an OK when it has finished. Since I left the original IOS in place, I need to specify which IOS I want the switch to load at boot up. I did so with this command and then saved and reloaded the switch.

Router(config)# boot system flash:c3560-ipbasek9-mz.122-44.SE6/c3560-ipbasek9-mz.122-44.SE6.bin

Router# write memory

Router# reload

Proceed with reload? [confirm]

• Once the switch loads, login and confirm the new IOS version is running.

Router# show version

• Now that the new image loaded successfully, I can delete the older version and remove the boot system command.

Router# delete /force /recursive flash:c3560-ipbasek9-mz.122-25.SEE3

Router# no boot system

And that’s it. The switch has been upgraded, tested, and the older version removed.

Of course this can be avoided by manually copying the running configuration for safe keeping, but we like automatic. The kind of automatic that we don’t have to worry about. The kind of automatic that Cisco provided to us with the ‘archive’ command starting with the IOS versions shown in Table A.

Table A: Archive command release history from Cisco.

The archive command allows you to create a copy of your configuration manually, periodically, or when the configuration is stored in NVRAM via FTP, TFTP, HTTP, or RCP.

In this example, I’ll being configuring the router to copy the configuration to a Windows 2003 FTP server  every time the ‘write memory’ command is issued. The file name is built on the routers host name, appended with “-x”, where “x” is an incremental number.  I’m also using the credentials of an Active Directory user, that I created for this purpose,  to allow the router to connect to the FTP server.

The FTP server address is: 192.168.1.50
Username: stevenson\netadmin
Password: n3t4dm1n

First we’ll configure the router with the FTP username and password.

Router(config)# ip ftp username stevenson\netadmin
Router(config)# ip ftp password n3t4dm1n

Now execute the ‘archive’ command.

Router(config)# archive

Now specify the path for the configuration archives

Router(config-archive)# path ftp://192.168.1.50/$h
Router(config-archive)# write-memory


The &h in the path instructs the system to use the hostname of the router when naming the archived configuration. And write-memory causes the configuration to be archived each time the write memory command is issued.

That’s it! You now have your router setup to automatically archive/copy your most recent configuration file to an FTP server for safe keeping. To test it out either enter:

Router# write memory

or

Router# archive config

Now check your FTP server and you should find the archived copy of your routers configuration.

If you want the router to archive your configuration at a desired interval, you can do that too by using the time-period command followed by the number of minutes that you want the archiving to wait between archive creation.

Router(config-archive)# time-period 10080

If you want to see a list of archives with the most recent highlighted, simply use this command:

Router# show archive

Now that you have the configuration backed up and can see the listed archives, lets look at restoring from one of the archived configuration files. Decide which archive file that you want to restore, from the list you saw when you issued the show archive command and enter that name as shown:

Router# configure replace ftp://192.168.1.50/Router-1

This will apply all necessary additions and deletions
to replace the current running configuration with the
contents of the specified configuration file, which is
assumed to be a complete configuration, not a partial
configuration. Enter Y if you are sure you want to proceed. ? [no]:y
Total number of passes: 1
Rollback Done

After you see “Rollback Done”, your selected archived configuration is now back in place on your router.

I’ve deployed this solution to a mix of Cisco routers, switches, and voice gateways and let me tell ya, it’s a nice feeling to know that all of those configs are being backed up automatically. Now if I have a failure or issue a bad command I can quickly and easily get things back to the way they were previously.