halfabiscuit wrote:That sounds very much like the problem I had. You could ping the loopback (127.0.0.1) all day but pinging a real address on the end of the wire would usually work for 20 seconds and then die.
I got mine RMA'ed and the replacement I got back has been rock solid.
I experienced similar symptoms today when installing a powered USB hub.
In the original configuration the keyboard and mouse were connected to the two USB ports on the RPi and I made a direct wired ethernet connection to my home internet router. The RPi internet connectivity worked fine: tested using ping from the command line and by connecting with a browser (Chrome and Midori).
In the new configuration I attached a 7-port (Hama) powered USB 2.0 hub to the RPi and connected the keyboard and mouse to this hub. The internet connection was via the same wired ethernet as before. The RPi obtained an IP address at startup and I was able to ping external hosts from the command line immediately after booting. However, after starting the windowing system the command 'hostname -I' took a long time to execute and usually timed out without returning an IP address. Occasionally it did return an IP address, but it was still impossible to ping remote hosts or to connect to the internet using a browser.
As a temporary solution, I have removed the USB hub and returned to the original configuration which still works fine. However it is not fully clear to me what is the root cause of this problem, and I would still like to attach a USB hub in the future to add more peripherals. My first idea would be to try a different USB hub, but the post quoted above suggests that it could also be a problem with the RPi itself ....