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Router reconfigures PC's and they can no longer access the internet via hardwired connection to DSL Modem.

Hardware Information:

  • Buffalo Wireless Router/access point, Model: WZR-HP-G300NH-AP
  • DSL Modem: Generic (actually not sure of manufacture).
  • Service Provider: TOT (Thailand)
  • Laptop-1: Windows XP and Belkin PCMIA Network Card
  • Laptop-2: Windows XP unknown network card & Wifi
  • Laptop-3: Windows 7 unknown network card & Wifi

Outline of Problem/actions taken:

After a recent power failure the router and laptop-1 connected to router were no longer able to access the internet. Actions taken to try and recover internet access:

  1. Using Laptop-1 tried to configure Router with PPPoe settings using software from Router Manufacture.

  2. During the installation process a Timeout error was experienced, unable to connect to WAN.

  3. Used Internet Explorer to communicate directly with Router using IP address.

  4. Changed settings to use PPPoe settings given by ISP.

  5. Router was not able to communicate with Internet.

  6. Repeated steps 1-4 again with no success.

  7. Reset Router and DSL modem.

  8. Repeated steps 1-4 again still no success.

  9. Tried connecting Laptop-1 directly to DSL to gain access to internet to research problem.

  10. No Network connection with DSL could be established…connection would be established for a second and then be lost and didn’t appear long enough to actually connect to DSL.

  11. Replugged LAN back into Router and connection was regained with laptop-1.

  12. Replugged Laptop-1 directly into DSL and again unable to establish network connection.

  13. Uninstalled network card and all of its drivers on Laptop-1.

  14. Reinstalled network card and drivers and tried connecting directly to DSL.

  15. Still unable to make network connection.

  16. Plugged DSL into Laptop-3 and Internet connection was established.

  17. Being Laptop-3 does not have a CD-Rom, Laptop-2 was tried to connect to the router.

  18. With Laptop-2 steps 1-7 ended up being repeated without success.

  19. Tried plugging Laptop-2 directly into DSL and again no network connection could be established.

  20. Using Laptop-3 with a direct connection to DSL downloaded latest Router FW.

  21. Installed router FW using Laptop-1.

  22. Tired the installation process again without success.

  23. Being desperate reinstalled OS on Laptop-1 still not success.

  24. Tried using “ipconfig” with router to see what was going on without success.

  25. With laptop-1 connected to DSL went through the “ipconfig /…” inputs to see if anything made a difference. Being the network card was not able to make a connection this provide very little information “media disconnected”. So now I have a router and two laptops which are unable to connect to the internet and sure could use some advice/help.

share|improve this question
What is connected to what and how? Is the modem connected to the router's WAN/Internet port? – David Schwartz Apr 3 '12 at 8:21

It's a bit of a long shot, but many ISPs limit the devices that can access the connection through the modem based on MAC address. If devices other than the primary attempt to connect directly through the modem, they'll get no connection. (And too many different devices can actually cause the connection to get taken down.)

It would be worth contacting your ISP and asking them to reset your connection so that the next device to connect can become the primary. Then connect through your router to establish its MAC address as the primary. (Then all others connecting to the router will look to the modem like the router's MAC address.)

Alternatively, if Laptop 3 is still able to connect directly via the modem, find Laptop 3's MAC address and then find the setting on your router that allows you to set it to a new user-defined MAC address. Use the address of Laptop 3 and see if that allows the router to connect. (Some routers have an automatic button to perform this, cloning the MAC address of whatever machine is configuring the router)

Good luck!


share|improve this answer
Thanks for the suggestion. I changed the MAC address on Laptop1 to match laptop3 and was still unable to conenct directly to the DSL. I have since removed the Router/WiFi from the debugging process and have contacted my service provider about reseting the DSL to allow multiple PC's to be connected. Still not sure if this is the problem, but the network connection on the two laptops work just fine until I connect to the DSL modem. Hopefully, I will have positive results tonight. Thanks again for your help. – zchads Apr 5 '12 at 9:20
Not sure what the exact problem was but things are back to normal after replacing the DSL Modem provided by ISP. The two PC's using XP and wireless router now are able to connect through ethernet connection. Seems like the original Modem from TP-Link was able to block or became configured after the power failure such that the systems with XP and the Buffalo Router could not connect to the modem. Thankfully a new DSL modem with wireless was not very expensive and I was able to resolve my problem this way. Will be interesting to see if the problem reappears during the next power failure. – zchads Apr 18 '12 at 4:54
Possibly the router was damaged from a surge when power came back on? – Neil Neyman Sep 9 '13 at 16:32

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