Local network only functionning when desktop is running

I have a dlink DIR-636L router and I have a very strange issue with it.

My local network only works when my desktop is running. When it's off, all my other computers have the "No internet access" warning. When I turn on my desktop, suddenly the network is fine. The issue happens both with wifi and cable.

The only thing I could think of is that the router doesn't have dhcp enabled and that my desktop is handling addressing on the network but the router's control pannel says dhcp is enabled.

Does anyone have a clue of what could be causing such a weird thing?

SBSTP

Posted 2013-05-13T04:17:40.063

Reputation: 123

I don't believe any desktop edition of Windows is capable of serving as a DHCP Server, only as a DHCP Client. The ability to serve as a DHCP Server is isolated to Server editions of Windows. Are all the other computers using wireless? – Davidw – 2013-05-13T05:23:34.543

how about your tcp/ip setting ? – matzone – 2013-05-13T06:25:36.233

I have installed a Windows Server 2008 but I have not used it in a while, I rarely every run it. Do you think it could have bugged my network in some may? I don't remember installing a DHCP server though. – SBSTP – 2013-05-13T12:26:07.323

Answers

Most likely, you are using the router only as a bridge and using your desktop as a router. If you ever specially configured your desktop to work with your ISP, you need to undo that special configuration. You also need to make sure your Internet connection is connected to the router's Internet port (the yellow one) and not a LAN port (the black ones).

David Schwartz

Posted 2013-05-13T04:17:40.063

Reputation: 58 310

Try to disconnect your router from your desktop computer. See if you have any internet whatsoever on the other computers.

Try to reset your router to its default settings (by going to its address), and also be sure that you unplug it from its power source (to do another reset).

Make sure that the router is directly connected to your modem, not to your computer that in turn is connected to the modem.

Most Importantly: Disconnect router from your computer and connect it directly to your modem. If this doesn't work, reset your router using the methods above.

I hope this helps. (if it does, please confirm my answer)

HelpingHand

Posted 2013-05-13T04:17:40.063

Reputation: 351

I have done more testing and it seems that the wifi only works when the computer is turned on, but it doesn't matter if the computer is actually connected... I thought it could be some electrical related issue, and I changed the router's location and the problem persists. This is the weirdest thing I've ever seen. I also updated the router's firmware, and reset its config to default. rgfgfhgdgdjhf – SBSTP – 2013-05-14T19:14:12.570

I have had the problem where all devices on the network were running their connections through my iPhone because I had used arp-poisoning from the phone while pentesting my network. This issue was solved by resetting the router AND resetting each wifi-connected device's wifi profile. You can do this by deleting the wifi connection from the device, and reconnecting to wifi. Try this. The problem may not be your router anymore. – HelpingHand – 2013-05-15T16:12:16.053