SB8200 2nd Port

[andriaj]

I have the same modem and cannot use my 2nd port for a wired connection.  What are we supposed to do if additional IP addresses are discontinued in our area?  How am I expected to run a mix of wired and wireless connections in my home without this?

[lesmikesell]

Pretty much everyone runs a mix of wired and wireless connections in their homes these days without needing a separate public IP address.  

[andriaj]

Maybe I'm just not properly understanding what I should be doing.  I can only run either the wired connection or a wireless connection from my modem because comcast doesn't allow both ports to be in use simultaneously.  They are saying in order to enable the second port usage, an additional IP address is needed.  Is there a different way to accomplish this?  

I should probably have prefaced this with "i'm not a networking engineer and don't profess to know much about networking".  I just want to figure out how to have a wired connection to my TV while also allowing for wifi for the rest of the home's devices

[lesmikesell · Accepted solution]

The SB8200 is just a cablemodem.  Normally you would connect a single cable to your router that handles both wifi and your private wired network.   That is, the router gets the one public IP on it's WAN port and everything in your home is connected to the private LAN ports on the router or over wifi.  It is very rare to need anything else.  If you used a leased xfinity gateway it would handle both functions in one device, but a separate router should work as well.  Doesn't your wifi router have additional wired LAN ports?

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[RobertWy]

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@andriaj wrote:

I have the same modem and cannot use my 2nd port for a wired connection.  What are we supposed to do if additional IP addresses are discontinued in our area?  How am I expected to run a mix of wired and wireless connections in my home without this?

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My Xfinity XB6 Gateway modem only has one ethernet port.  I have an 8-port unmanaged switch attached to that port and my network plugs into the switch.  Works with not issues.  I actually have a second 8-port switch connected to it for my den.

https://www.amazon.com/gp/product/B001QUA6RA/ref=ox_sc_saved_title_8?smid=ATVPDKIKX0DER&psc=1

[andriaj]

Thanks for the replies and extra details.  I think I have my brain wrapped around this now.  I have 2 ports on my router, so I will hook a switch up there and should be able to get things working that way.   My problem was compounded because the hardwired connection was appearing not to work due to a bad ethernet adapter.  Now that I have that resolved, I think I'm able to get everything working as I had hoped.  Thanks again.

[lesmikesell]

The SB6 gateway @RobertWy mentions combines a cablemodem and a wired/wifi router in a single device.  The SB8200 is just a cablemodem so you need to connect it to a wifi/wired router, not a switch. You could add a switch on the other side of the router if you need more ports but you need the function of a router to manage your local network.   You mentioned you were already connecting to something for wifi.  What device is that, and doesn't it have some additional wired ports?  If so, that is where you should connect the rest of your wired devices.

[BruceW]

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@RobertWy wrote: ... My Xfinity XB6 Gateway modem only has one ethernet port ...

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No, it has two Ethernet ports. But when you have the device in bridge mode, you can only use one of the ports. Please try to keep this straight!

[RobertWy]

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@BruceW wrote:

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@RobertWy wrote: ... My Xfinity XB6 Gateway modem only has one ethernet port ...

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No, it has two Ethernet ports. But when you have the device in bridge mode, you can only use one of the ports. Please try to keep this straight!

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Yikes!!  I forgot.  Thank you.