Internet not working when connected directly to a modem

[captainbowie123]

One morning i turned on my computer and my internet wasn't working. It was working for my roommate who was connected to the same modem. I tried everything and it didn' help. Then i connect my cable into a routher that was connected to a modem and my internet suddenly started working again. Same thing happens when i go visit my parents place. If im connected via wire directly to a modem my internet won't work, and if i connect myself to a routher that is connect to the same modem, then my internet works again.

The problem is that any torrenting or high internet usage makes me lagg, and id like to connect directly to a modem agian.

 

[alexoiu]

If directly connected to the modem, you have to configure the internet connection (username and password provided by the ISP).

 

[captainbowie123]

What do you mean? I didn't get any username or passwords from my ISP and i never had to do that manually before. It was always working, then 1 day it just stopped and now it says "local area connection doesn't have a valid ip configuration".

 

[alexoiu]

Try contacting your ISP.

 

[hang-the-9]

A Modem, unless it's a Gateway with a modem and router in one, will only provide access to one computer at a time. If you swap cables around from one computer to another it can take a while to pick up the MAC of the new network card and register it so it's working on the new connection.

If you have a router connected to the modem that is what you want to connect to anyway, so you connecting to a modem where you have a router available is doing the wrong thing. Unless that "modem" is a gateway, and in that case you do not want to have both a router and a gateway setup unless the router is setup as a simple switch with DHCP and NAT turned off.