What now what??? NO CARRIER on opt2 em2 interface!!!

[TechDope]

Hello internet... So followed instructions here (Option 1: Dynamic IP Address)...

https://homenetworkguy.com/how-to/connect-pc-directly-to-opnsense-interface/

...to activate an extra (DMZ) port and interface (opt2 em2). However, the lights are off and no one is home 

So not getting any lights on the Opnsense router for em2 or any connection when plugged into Windows 10;

DMZ interface (opt2, em2): Status no carrier

What does "No carrier" mean and is there something else I should do to activate this port?

As a test I changed the new DMZ firewall rules to match the LAN rules, and also restarted the router. But still hasn't activated em2. When you activate a port on a router, does it immediately activate showing as "Up" and with lights?

Is there any thing else on an Opnsense router that would stop a port from activating?

Thank you... and a million thanks yous will be awarded to the successful problem solver 

[chemlud]

"no carrier" simply means that there is nothing plugged into the port (that tries to connect, e.g. to DHCP)

[TechDope]

Ah ha! Thanks for that, I think I got it working! I have been using a new Cat 7 cable, but when I used a regular Cat 6, I got lights and a connection! Guess my router doesn't like Cat 7. Doh!