I recently joined a company that has Cisco switches throughout the network. My boss has told me that my first task is to upgrade the switches to the latest available firmware. I have been around Cisco switches some but haven’t done this particular task before. Can you give me an idea of the best way to do it?
I recently joined a company that has Cisco switches throughout the network. My boss has told me that my first task is to upgrade the switches to the latest available firmware. I have been around Cisco switches some but haven’t done this particular task before. Can you give me an idea of the best way to do it?
— Via the Internet
Carefully, very carefully.
After you get the login information for the switches, I would get an inventory of each switch. Be sure to note the model number of each switch, the amount of DRAM and flash memory for the switch and the current firmware that the switch is currently running on. Then, go to Cisco’s Web site. If you don’t already have a Cisco CCO login, now would be a good time to have one. If your department has a “departmental” login, get that information and log in to the site. Download the latest firmware for each switch. Depending on the switch, you may find that there is either a .tar or a .bin or both type of files. I would suggest getting both.
Once you have the firmware files for all the switches on the network, you need to assemble tools for the upgrade. Get a laptop that has both a network card and a serial port. Although it is possible to upgrade a switch to newer firmware from across the network, I generally prefer to be next to the switch so I can watch things more closely. Make sure that you have both a network cable and a Cisco console cable setup. I prefer to have both a network cable and a console cable connection to the switch I am upgrading. This way, I can watch the switch via a console connection and note any errors that might not be readily apparent when using the network connection to do the upgrade. You will also need a tftp server to make the new firmware available to the switch. Solarwinds.net has one available as a free download.
For each switch, make a backup copy of its firmware, just in case there’s a problem during the upgrade and you need to revert to the original firmware. I would also suggest getting a copy of the current switch configuration – just in case this were to get wiped out or otherwise damaged. While you’re at it, back up the configuration for all the switches on your network – again, just in case you need the information. Depending on the amount of memory in the switches you are upgrading, you may find that you need to delete the existing firmware before you can install the new firmware.
Assuming the firmware upgrade works, you will need to reboot the switch for it to take affect. This is where watching the switch via a console cable comes in handy. You will be able to watch the switch as it loads the new firmware and record any errors that occur during the reboot process.
Since this looks to be your first time doing this, see if there’s a spare switch in your department you could use for practicing on – and developing an upgrade checklist – before moving onto the production switches.
Review the release notes for each firmware revision that you download. You will notice that for some switches, you will need to use the enable command followed by the tar command pointing to the tftp server on your computer to install the new firmware. On other switches it will be a case of just tftp’ing the new firmware in place. In both cases, remember to check the boot flash variable and note its current settings. You will probably have to change the statement to reflect the newer firmware being installed before you issue the reload command.
You shouldn’t have a problem doing the upgrades, just take your time. Since a restart will be involved for all the switches, find out before you get started when will be a good time for all the departments that will be affected by the restart to be down for a few minutes and let that help you decide when the best time to do the upgrades will be.
