Who is your internet service provider?
Please list the make and model of your modem and router?
Do you have any additional network hardware, like additional routers or managed switches? This would be the Orbi
I have 3 Orbi’s, one directly connected to modem, the other 2 are wireless through house for internet connectivity. No other routers or switches
Does your network have any VPNs, proxy servers, or enterprise-grade security?
You are most likely experiencing a Double NAT situation and this prevents port forwarding for ARC. Because you have only one router, the most likely cause is that Century Link is using an addressing technology called CG-NAT (Carrier Grade Network Address Translation).
Before doing anything else, you’ll need to confirm with your ISP that you have a public IP, and that they aren’t using CG-Nat. You can prompt them with the following questions:
Have you implemented carrier-grade NAT for my account level?
Have you fully implemented IPv6, or do you have IPv4 addresses available?
Can I request a public or static IPv4 address to support port forwarding?
Are there any port numbers you have reserved at the ISP level I should be aware of?
Note: This may be painful if the Century Link support is clueless. They won’t know about Roon, but you could try telling them that you are trying to set up port forwarding for a PlayStation 4. (It uses essentially the same port forwarding solution as Roon ARC)
Yeah, your machines are behind your router’s NAT as usual, but there’s another layer of NAT around the customer routers. Whether it’s possible to change that by getting you off the CG-NAT is exactly the question you have to ask Century Link.