Assigning a second IP address to an Arris SB8200

[ಠ_ಠ]

After spending 3 hours speaking to 12 scripted reps, I am trying my hand here for someone who can help me out.

I have an Arris SURFboard SB8200 cable modem. I would like to be able to make use of both ports, so one of the ports can be used as a direct line, and the other fed to a router. My understanding is that this requires a second IP address to be assigned to the modem. I would appreciate if a Comcast rep could tell me:

A: Whether this is possible under a residential plan in my area.

&

B: How much this would cost.

Thanks.

[ಠ_ಠ]

I dont believe anyone is allowed to use the other ports on modems like the SB8200 and MB8600 currently allowed unless if having another IP.

Look at this link and see if an additional IP is available for your area.

https://www.xfinity.com/support/rate-card/

Another link for reference:

http://forums.xfinity.com/t5/Your-Home-Network/SB8200-Ports/td-p/2915827

[nerdburg]

If a second residential IP is available (it's not in many areas), it's about $7/month.  But I don't think that's what you really need. Aren't both ethernet ports already active? Why wouldn't you just plug into the router?

[jweaver0312 · Accepted solution]

I dont believe anyone is allowed to use the other ports on modems like the SB8200 and MB8600 currently allowed unless if having another IP.

Look at this link and see if an additional IP is available for your area.

https://www.xfinity.com/support/rate-card/

Another link for reference:

http://forums.xfinity.com/t5/Your-Home-Network/SB8200-Ports/td-p/2915827

[ಠ_ಠ]

@nerdburg

It is indeed what I need. Only one port is usable at a time without a second IP address, according to Arris' own documentation.

I need a direct line from the modem concurrently active with a line to the router, for diagnostic purposes.

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@jweaver

Thanks for the links, this is exactly what I needed!

[jweaver0312]

Just wanted to say if the only diagnostic use you are going to use it for is signal stats if you had a problem you dont need to get a second ip. For example, if youre internet is slow behind your router (192.168.1.1) and you wanted to check the modem stats, you can go to 192.168.100.1 right from any connected device.