I have comcast high speed internet attached through the modem to a Netgear router. I connect my computer by ethernet cable to the router and my wife connects wirelessly. Everything works perfectly until my son comes home from college and tries to connect his computer either by wire or wirelessly. He immediately connects and gets internet but in the process my wife and my computers get kicked off and we can't reconnect until he disconnects. Any ideas what's going on?

I'm not sure exactly what's going on, but have you tried creating a new network connection on his computer. Or on the other two?

Hi,
U have to check the router's configuration. It might be configured to support only a certain number of connections, and that is why u are getting cut off. Check the configuration of the modem as well.

His machine may also be set for a specific IP not for automatically obtaining. That might cause a conflict.

This certainly ISN'T an issue with your router, but as Scott suggests I feel that your son has set his machine to a static address which is causing a conflict with the other machines.

Make sure ALL your machine are set to DHCP enabled automatic IP address, this should resolve your issue.

He connects by cable, that means usually a static IP, the wife connects wireless, that is automatic. But when the sun comes home they both get disconnected. If it were to be an IP conflict, only the two computers with the conflict would be disconnected. In this case the sun and mother or father. That is why I was thinking of a configuration reason.

When the sun comes home? Isn't the sun already "home" at the center of this solar system? Are you claiming the problem is sunspot activity?

:D :D :D :D
Couldn't resist.

When the sun comes home? Isn't the sun already "home" at the center of this solar system? Are you claiming the problem is sunspot activity?

:D :D :D :D
couldn't resist.
GROAN...

He makes a good point about the IP address conflict, also most universities do not give out static IP addresses. At least the ones that my wife used to work at don't... too much of a hassle. It would be a good idea to check it though and if it is static set up an alternate configuration that will use DHCP. Also wouldn't hurt on his machine to flush the DNS out. From a dos prompt: ipconfig /flushdns.
I'm assuming he's running Windows...

You also can't rule out that he may be running something on his computer either knowingly or unknowingly that could cause this as well.

How about, if the son's computer was acting as a DHCP server somehow?

Do an ipconfig /all from the cmd prompt and report what's different when the son connects.
It might provide a clue. Copying and pasting info to/from the cmd window is tricky.

How about, if the son's computer was acting as a DHCP server somehow?
I thought about that but it wouldn't explain why they both get bumped when he connects. A second DHCP server would only give them a different IP address when the lease on their current address expired.

I was thinking more along the lines of a program or something like a bit torrent client that's seeding and consuming all the bandwidth but even then they should be able to get on and if they're already on they shouldn't get bumped.

I'm just thinking out loud here... (so to speak)
Feel free to try this...
When your son is connected and you're kicked off, open a dos window.
Type ipconfig /flushdns.
Type ping Google (http://www.google.com)
Do you get an IP address? If yes then you are still connected to the internet because it looked up the address. Did it get a reply?

What happens if you turn his computer on but don't log in? Do you still both get kicked off?