How to switch LAN (mgmt interface) from copper to sfp+?

[alto]

I currently have my management interface (igb0) connected with copper cat6 to my switch, this is also the parent interface of all my vlans. I want to change this to run over sfp+ though, i.e. to use interface ax0 instead. But what is the procedure to do this so that I don't completely lock myself out of the router if I change the management interface device from igb0 to ax0 and something doesn't work?

[pfry]

Do you have some constraint that would not allow you to apply or copy (depending on your version and rule architecture) your management interface ruleset to an additional interface?

[nero355]

I currently have my management interface (igb0) connected with copper cat6 to my switch, this is also the parent interface of all my vlans.

You should split that up to two seperate interfaces :
- Management Interface
- Empty Interface with all VLANs on it.

I want to change this to run over sfp+ though, i.e. to use interface ax0 instead.
But what is the procedure to do this so that I don't completely lock myself out of the router if I change the management interface device from igb0 to ax0 and something doesn't work?

Think about what you need and what you are doing and you will probably come up with something like this : https://forum.opnsense.org/index.php?topic=51018.msg261070#msg261070