Cable modem connected to main router running DD-WRT. Two cheap Rosewill routers (http://www.newegg.com/Product/Product.aspx?Item=N82E168...) also running DD-WRT are connected to the main router in what I believe is a client bridge setup. These routers connect to the main router wirelessly. They do not broadcast wireless signals and the computers and switches connected to them are done so with a wired Ethernet connection.
The network works perfectly fine most of the time. However, when a particular laptop is connected to the network it seems to connect to the local network, but there is a yellow exclamation point and it does not have Internet connectivity. As soon as I power off a particular desktop, the laptop can connect to the Internet just fine. This particular desktop is connected to one of the Rosewill routers via Ethernet.
What can I do to fix this? Previously the desktop that seems to be causing the problem was setup with a static IP. I removed the static IP setting and rebooted the router and modem and it worked fine for a couple of weeks, but more recently the problem has reoccurred. I would like to not reset all the routers to the default settings. I can't remember how I setup the two bridges, but it took a lot of trial and error that I would prefer to avoid going through again.
Off the top of my head, I would guess that you have more than one router acting as a DHCP server. Two devices with the same IP address on a network would cause this problem, and when you switched the desktop from static to dynamic seems to reinforce my idea. Perhaps one of the routers did not have the static IP on the exclusion list, so it was accidently assigning the same IP twice.
I would go through the settings on each router and make sure only the router running a DHCP service is the main one.
ANSWER: My friend, I had the same situation, it would come and go, did tons and tons of searching and...thank God I found my problem after all the ip4, ip6, all kinds of starting and stopping things ect. After a fresh install of Windows 7 last night and the system was flying like it should, yeahh at 56mbps...it stopped again!!! "No Internet Connection" You got to be kidding me, this thing is fresh..I started rolling back different drivers that I had started loading and then it was back, hmmm. I started re-loading them and checking and when I got to the "USB 3.0" controller....there it was!!! When ever I would plug something into it, an external drive, flash drive or God forbid my "Wireless" adapter, dead in the water again!! What....after all the searching, I never heard a word about this, you got to be kidding me. I did a little searching on it and oh yeah....they know;) I actually found a bulletin from "INTEL" stating that the 2.4ghz wireless adapters could have a problem functioning since the USB 3.0 unit produces a "NOISE" or even a frequency that interferes with these things!!! You got to be kidding me, oh yeah!! I even found an HP post on it but...really not much more then that at all!! SILENCE...ridiculous, they need to fix their hot 3.0 USB flash in the pan system. I just purchased a 4 port one and am waiting on a "card reader" with another 4 ports!! Oh my goodness, what a waste. They seem to stop broadcasting after a minute or two of pulling the connection but that kills surfing while trying to do anything with the port. I couldn't believe it but thank God I found it. Please pass this on and sure hope it helps you...now that is easy;) Here's the INTEL bulletin link to see for yourself. God bless, Ben. Link:http://www.usb.org/developers/whitepapers/327216.pdf