My experiance is not that high, please bear with me.
We operate two M4300-8X8F in a stack configuration untouched since a couple of years.
As I need to add a new stack member (also M4300-8X8F), it is probably a good time to upgrade the firmware. At the end, all switches must have teh same firmware version, right? I do not have a reserve hardware.
The currently running firmware is 12.0.11.8 (active image2 on both stack members)
The latest available firmware is 12.0.17.10
Questions:
Is it possible to upgrade directly from 12.0.11.8 to 12.0.18.10?
Should I upgrade before extending the stack with unit 3, or afterwards?
Are there specifics I need to take care of? What is the best way to proceed?
Is there a chance that the configuration will be messed up?
What are the ways to minimize risc?
I guess I can copy the current version 12.0.18.10 via HTTP File Upgrade to image1 on both stacked devices, and the third unit too. Than change the next active image to image 1. A major question is probably if joining the stack before or after the upgrad is better.
I suggest you to update the existing M4300-8X8F stack and the new M4300-8X8F switch in a ladderized manner. First, update the firmware from v12.0.11.8 to v12.0.11.10. Then, update the firmware again from v12.0.11.10 to v12.0.11.11 and so on until you reached the latest firmware which is v12.0.17.10. You can download the M4300 firmware versions here.
After you have upgraded the firmware of both the M4300-8X8F stack and the new M4300-8X8F switch to the latest firmware, you can now add the new M4300-8X8F switch to the existing M4300-8X8F stack.
Be sure to do the steps above during non-production hours to avoid downtime.
