Can only have one thing connected to the internet

[DarkMassacre]

A friend of mine just got internet service set up today but is having problems that I don't know how to deal with. He can connect to the internet just fine, but only one device at a time. When he logs onto Xbox Live, he can't access the internet with his computer. He got an error message that stated that his IP address was declined.

 

[Hefemeister]

Is he using a router?
Is his router acting as a dhcp server?
are his devices set up to obtain ip automatically or are they set with a static ip?

 

[SparkMonkeyHellion]

It's because ISP's limit you to one IP address per modem.

You'll need to connect everything into 1 router, and then connect the uplink port of that router to the modem - so that way the modem only sees 1 IP address.

We had the same problem when we got a new switch to replace an aging router. The switch doesn't assign IP addresses, it just passes traffic (layer 2 device, rather than layer 3 device).

Now we have a switch to gather all the signals together (Xbox's and computers plus my AirPort express) and then we run that switch to the old router and then into the modem. The router bottles everything up into 1 IP address, so the modem from our ISP can't tell the difference.

 

[DarkMassacre]

Yes, he's using a router.
Yes, it's acting as a DHCP server.
His IP is obtained automatically.

Well, he did what you suggested Spark, but he got another error message stating "192.168.1.64 in use by 00:12:5a:77:49:1e, DHCP Server 192.168.1.254"

 

[Hefemeister]

what ips are given to the pc and the xbox?

Sounds like an ip conflict.

 

[SparkMonkeyHellion]

is anything set to static?

Modems also try to act as a DHCP server, because they assume that you'll just have a computer attached to it....

however if you get a "already in use" then you likely have a static IP set. Or maybe you just need to restart the end nodes (like the 360 or whatever) so it grabs a new address.

 

[DarkMassacre]

Well I know that his computer's IP address is set to automatic. I'm fairly sure his 360's is too, not sure though.

EDIT: They're both automatic.

 

[Hefemeister]

look in the router it will show you what ip addresses are given to what mac address.

when the xbox is connected to xbox live on the computer you could do
ipconfig /release

then
ipconfig /renew
from a dos prompt on the computer to get a new one