ARRIS Surfboard SB8200 question

The SB8200 is a standalone cable modem and does not include a built-in DHCP server. As a result, when your internet service provider (ISP) activates the modem, it typically assigns only one public IP address, which supports a single internet connection.

If you wish to use both Ethernet ports on the SB8200 simultaneously, you would need to contact your ISP and request the activation of a second public IP address. However, please note that not all ISPs offer multiple public IP addresses for residential customers.

For more details on the functionality of the SB8200’s Ethernet ports, please refer to the link below:

 https://arris.my.salesforce-sites.com/consumers/articles/knowledge/SB8200-Ethernet-Ports

If you want to connect multiple devices, you’ll need a separate router connected to the SB8200. From the router, you can then connect multiple devices. Alternatively, you can return this modem and opt for a gateway, which combines both a modem and a router, allowing you to connect multiple devices via Wi-Fi and wired connections.

Unfortunately Comcast does not have compatible modems for Comcast business which are both modems and routers. To be clear what I was asking is adding a multiport switch between the modem and other devices going to work so I don't have to change cables. So I would only be using one port on the modem and I would connect the ethernet cable to the multi Port switch and then connect the router to that. Is that going to solve my problem?

You need to router to assign private ip addresses. So it needs to go modem---->router---->switch

You can’t go modem--->switch---->router. It wont work