Do interface dev numbers need to match?
I understand I can use different hardware, I just need to match the number and order of the interfaces. I assume it's ok to have a greater number of NICs in one box as long as they're not assigned? Also, is the order that matters what's listed in the GUI, or are we talking about the order of the device interfaces, em0, em1, etc?
For instance, I have the following setup.
Box 1 WAN1 - em1 LAN - em0 WAN2 - em2 SYNC - em3 Box 2 WAN1 - em5 LAN - em2 WAN2 - em4 SYNC - em3
The order the interfaces appear in the assign interfaces window are the same, but the device numbers are in a different order. Do I need to switch things around so the ems match?
You're OK. So long as the order of assignment is the same it doesn't matter how they line up physically.