Wired connecton not working with Network Manager

Sorry if this has been discussed elsewhere. I am on OpenSuSE 13.2. My wireless connection works fine, but I can’t establish a stable ethernet connection: it occasionally works when freshly created (not always) but when I check again at a later time it no longer works. Network Manager does try to bring the connection up, but it typically fails with just a message of “Never used”.

What is weird is that, as far as I can say, the problem started after I got a new modem/router (AT&T Uverse), never happened before. My laptop: Dell Precision M3800. This laptop doesn’t have a regular ethernet port, I need to use a usb-ethernet converted. The problem doesn’t seem to be present on my other (older) laptop with a regular ethernet connection.

I can’t see anything on the modem setting that would indicate any restrictions for ethernet connections.

At work, the wired connection does appear to work but I have problems uploading material on some websites (inside my institution’s network) where I never had any issues before. What makes matter worse, is that I have a poor wireless connection at work, and I need to use wired connection, and I need to upload material.

These symptoms would suggest some problems with the modem, but the issue is not present in Windows. Any help would be appreciated. Thanks!

Recommend you start with basics, ordinary first steps troubleshooting a network connection.

First, check your physical connections… Bad wire connections? Is your NIC indicator light a steady green, or orange, or blinking? Each color and whether blinking indicates a different state. If the light isn’t lit at all, that’s a big problem. And, check both ends of your patch cable (assuming patch cable).

After you’ve checked your physical connections, next address your overall network management. You should turn off or disable your wireless when connecting wired (or vice versa). Your machine may not function properly with 2 connections to the network unless you are doing something advanced, but currently am assuming you’re trying to configure very ordinary connections.

Once you’ve done the above, then start collecting information about your machine’s network connection and state.
The basic tool is “ip” and the following are commands that display your current address, then gateway.

ip addr
ip route

The above should return valid IP addresses, either statically configured or automatic using DHCP. If you don’t see what you expect, then you need to start your exploration based on what you see.

If you see valid networking results,
Then your next step is to verify your connections using PING, by address and by name.

Ordinarily,
The above should solve most networking issues.
If you continue to have problems or have questions about the above, then post your questions…

HTH,
TSU

What is weird is that, as far as I can say, the problem started after I got a new modem/router (AT&T Uverse), never happened before. My laptop: Dell Precision M3800. This laptop doesn’t have a regular ethernet port, I need to use a usb-ethernet converted. The problem doesn’t seem to be present on my other (older) laptop with a regular ethernet connection.

Your Ethernet to USB adapter could well be causing your connectivity issue. A quick online search turns up numerous results across different distros and operating systems generally.

More info about your hardware could be useful. The following will report all attached usb devices and the driver associated.

usb-devices

Since you mention you are using Network Manager, you could monitor ‘NetworkManager’ output in a terminal, using

journalctl -f|grep Network

That might help capture any pertinent disconnection events.

BTW, frequent disconnections might be due to USB power management at play. If that is suspected, it is possible to disable if necessary with a suitable udev rule

https://wiki.archlinux.org/index.php/Power_management#USB_autosuspend
https://www.kernel.org/doc/Documentation/usb/power-management.txt

Thanks deano and TSU,

It looks like the ethernet connection works now, at least at home. I will have to monitor it for a longer time to be sure, and check with the problems at work this week, to see if the problem with uploading data is still present.

I can’t quite see the explanation, and am not sure that this is what fixed it, but the only thing that I did was to uncheck the option to “Automatically connect to VPN when using this connection”. I have doubts because I remember having problems long before I consider using the VPN option, and because the VPN connection works without problem when started independently.