Loosing internet connection when new device connected

I have a strange problem and I have exhausted my limited network troubleshooting skills. Please help.

I have a My Net N900 router with several devices attached, both wired and wireless. Everything works great until I connect my laptop device that I bring home from work. When I connect the laptop I loose internet connectivity from all of my other devices along with the laptop. I am able to see my home network but I can’t access the internet. The loss of internet connectivity occurs within 5 minutes of connecting the laptop.

In my troubleshooting efforts I have learned:

  • I can turn off my wireless on the laptop and connect it via the wire. I loose internet access.

  • I can disconnect the wire, turn on wireless, I loose internet access.

  • When I loose internet access, I have to disconnect the laptop and usually have to power reset the router to recover although on at least one occassion I waited for a while and it recovered on its own after disconnecting the laptop.

  • I booted the laptop into safe mode (Windows 7) with networking and I do not have any problems. Everything continues to have internet access.

I am convinced that there is something on my laptop when booted in normal mode which causes the symptom but I don’t know where to look. Note that the laptop is configured to a domain for connecting to my network at work and when I boot the laptop at home I logon with the computer only logon. I do not have any issues running the laptop at work.

Any advice on what I can look for?

I think I found my problem. In the router settings for the N900 I changed “Enable DNS Relay” to “Off”. Now when I connect my laptop to the network I do not loose network connectivity.

Prior to changing the setting I ran the Windows network troubleshooter on two of my connected PCs and they both indicated that they were not getting a response from the DNS server. That is what prompted me to change the setting in the router.

Any idea what might be going on? Why does the problem only begin when I connect my laptop from work to my home network?

We are having similar issues now that our inlaws are here and both have ipads.  each day, the wireless stops working and I have to hard wire a connection to the router, log into it, and turn off and on the wireless, which seems to make it work again for all of the devices.  I got off the phone with tech support and they told me as a first step was to “clone my mac address”  I did that, the router powers off and back on again after about 90 seconds. 

They said if that doesn’t work to call back in to go to tier 2 for more advanced trouble shooting.

The only way I could get the ipads to work is to turn on the guess wireless for whatever reason, as a side note.