I'm planning to upgrade my system from V12 to V14, as it's the first time for me, I would request your advice regarding to below points.
1- is the V14 stable.
2- what is the best practice for upgrade preparation and upgrade process.
3- how to revert back to the old system in case of unsuccessful upgrade.
thanks in advance.
1. Every environment in terms of hosted applications, modules used on F5, traffic is different. But in general v14.x is out from quite long time so shouldn't be a problem. Only thing to consider is you may want to go ahead with 184.108.40.206 as it has fixes for latest CVEs F5 has announced and also has fix for the tmm bug.
2.If you have nonprod F5 environment do the update there first. Before update save ucs backup, perform license reactivation if software release date your are going to is later than your device last service check date.
3.you can reboot the device to it's old boot partition having v12 without any issue.