I've got a Dell XPS 17 L702X laptop that I move between different workplaces. Ethernet works fine at one location, but the other location is problematic. It worked fine consistently two or three months ago, but I've since reinstalled Kubuntu (KDE 4.9.3), so that might have something to do with it.

The last three times I've arrived at work, ethernet doesn't work properly. That is, it's extremely slow, often timing out. I can get webpages to load about 20% of the time, and if they do, they take about half a minute. I've tried pinging google.com, but just got an error.

Code: Select all

ping: unknown host google.com

FWIW I suspend my computer to RAM at home, then wake it up at work. I've tried both suspending to RAM or swap, then immediately resuming, but this doesn't help. What does work is if I hibernate, then start Windows (dual boot). Then, the ethernet works fine in Windows. Now, if I shutdown Windows and resume my linux session, and the ethernet now works in Linux too! This is a decent workaround, but obviously irritating (especially since hibernating to swap is erratic at the best of times).

Hmm, can you check to see if the DHCP request for your machine is completing successfully? This seems much more likely to be a network issue than a actual fault in the system. If it completes properly, then your machine should have a normal (non APIPA) IP address afterwards.

bcooksley wrote:Hmm, can you check to see if the DHCP request for your machine is completing successfully?

To be honest, I've not had this problem since my original post a month ago (I go this to workplace once a week). Before then, I had this problem consecutively for the previous 3 weeks or so. I'll test this if I see this issue again. Where do I find this information? I couldn't see it in the network plasmoid.

Unfortunately the applet does not show if the DHCP request completed successfully.
The best way is to monitor how long it takes to complete (a wired DHCP request shouldn't take too long to complete) and to check the resulting IP address afterward to see if it conforms to usually expected IP ranges.

I suspect I wasn't being assigned an IP address at all, but I'll check next time if I come across this problem again.

In that case, your system will have likely assigned itself a APIPA address. (169.254.x.x if I recall).