CM1200 modem one 1 LAN port has internet

[Mmatt6]

I had AT&T and recently upgraded to Xfinity. The AT&T configuration for internet/wifi was 4 LAN port modem/wifi combo, with 3 Cat5e ethernet cables in the home. One cable directly to iMac, one to PS4 console and one to family room TV. 

To save money I bought a CM1200 modem with 4 LAN ports and an Orbi mesh (1 router, 2 satellites). Xfinity tech said all 4 ports on modem can connect to internet. I have one LAN cable connected to the Orbi router, and that router connected via LAN to the iMac. Internet LAN on iMac works fine, WIFI throughout house works great too. 

Since I have these 3 LANs already in the home, how can I get them to connect to the internet?

On a previous thread I saw this --

>>one thing to keep in mind with the cm1200 that many people don't know. Only 1 port is usable for the average consumer.

Reason why it has extra ports is this.

1. port aggregation. you can aggregate ports 1 & 2 so they run together. most average routers don't currently support this feature. so if you're router doesn't have wan port aggregation, its a bit pointless.<<

My question is: do I have to get 2 additional Orbi routers to get the LAN cables to the PS4 and family room to connect to the internet or am I stuck with just 1 static IP address?

If anyone has a suggestion, please share. Thanks in advance....

[pic related]

[plemans]

Ahhh, reading off one of my prior posts 🙂

You're right. Only port 1 works on the CM1200 with xfinity (unles you're on a business class line or using wan port aggregation). 

Options if you need more ethernet ports? Buy a cheap gigabit switch. Much cheaper option

so go 

CM1200---->Orbi----Switch/satellites---->ps4/devices

[plemans]

again, the other 3 ports are pointless. You're not going to be able to get them working Just re-affirming that. Unless you want to pay xfinity for a business class line. The xfinity tech steered you wrong.