What should network settings be?

English Network/Internet
1

I just got networking back after 3 days of changing every setting I could find. Please tell me, even if generic, what my setting should be. Unlike a couple of other recent threads on losing networking, mine happened when I changed desktop themes and back again. The connection is so preposterous that I wonder if an update took place during a reboot when I changed the desktop settings.

Unlike the other threads, I have the 32 bit version of 13.1 and also the latest KDE.

I have an ethernet connection that previously was listed twice; once as enp2s8, which is the name of the card (not really a card but built into the MB) and also as eth0. I tried using a wireless connection and though recognized it could not connect to my router either. I tried removing all the connections, hoping a reboot would sort the hardware out. It did not. I took the firewall down to see if that was a problem. It was not.

Beside using yast to check settings, I used zenmap and wireshark and a root terminal to connect. None worked. All said the network was unreachable. All other devices in the house could connect.

I connected after I changed a hostname to the name of my computer. Now, I cannot find where that happened. So, I hope you can give me a baseline in case this happens again.

Looking at yast–>hostnames I see localhost and my wireless printer and a bunch of ipv6 listings even though I use only ipv4. I tried adding my router there but that did not work and I removed it.

Looking at yast–>network settings, I have “use ifup” under Global Settings; under overview, the card is the only thing listed and uses DHCP and is described as an ethernet controller, the old eth0 is no longer listed; Hostname lists my pc and domain; Routing lists my router as gateway but no device is listed with it.

Going back to edit the ethernet controller, it is listed in the External Zone of the firewall. When there was a listing for eth0, I think it was listed in the Internal Zone. What is the proper setting for the firewall?

Please evaluate the situation and tell me where I need to make changes or additions.

2

The network interface SHOULD NOT be listed twice, as that can cause problems.
See also the 13.1 release notes:
https://doc.opensuse.org/release-notes/x86_64/openSUSE/13.1/#sec.131.systemd-networkif

I connected after I changed a hostname to the name of my computer. Now, I cannot find where that happened. So, I hope you can give me a baseline in case this happens again.

I suspect your problem was actually caused by the duplicated interface. Changing the hostname might have fixed that, as YaST rewrites the network configuration in that case.

Looking at yast–>hostnames I see localhost and my wireless printer and a bunch of ipv6 listings even though I use only ipv4. I tried adding my router there but that did not work and I removed it.

You should not add your router there manually.
In fact as you use DHCP you should not have to configure anything, except the hostname if you want.
All other settings are fetched from your router in case of DHCP, so everything should just work.

Looking at yast–>network settings, I have “use ifup” under Global Settings; under overview, the card is the only thing listed and uses DHCP and is described as an ethernet controller, the old eth0 is no longer listed;

As I said, the device should actually be only listed ONCE, otherwise it won’t work.
You can rename the device there in YaST btw, if you want. (Edit->Hardware)

Hostname lists my pc and domain; Routing lists my router as gateway but no device is listed with it.

That’s ok. If no device is listed, it applies to all devices.

Going back to edit the ethernet controller, it is listed in the External Zone of the firewall. When there was a listing for eth0, I think it was listed in the Internal Zone. What is the proper setting for the firewall?

Depends on your use case of course.
By default the internal zone is not protected at all by the Firewall, so adding your only network interface there would be in fact equivalent to turn off the Firewall completely.
OTOH, your router most likely acts as a Firewall as well, or hides your network from the Internet (NAT), so you might not really need the Firewall anyway.
But the Firewall should at least not cause “network unreachable” errors.

3

Thank you, wolfie323.

I just saw a new problem. I have a backup computer in case I’m really stuck with the regular one. I just booted it for the first time in weeks. Running zypper ref, I get 366 updates. Running zypper up, it stalls after a few files with an error message that network is unreachable. If I press r for retry, it loads a few more then stops again.

It did that for the first 70 files and has not for the next 50. The setup is the same: 13.1 and up to date KDE. It is connected by cable to the router. If the router is busy with other devices, it would not give an unreachable error, would it? I don’t have that much going on: a multipage scan job and this internet activity.

Do I misunderstand what the error message means?

4

“Network unreachable” means that the router doesn’t forward your requests to the Internet most likely.

I would say this really sounds like a hardware problem. Probably the router, as it happens on two different systems.
Maybe try to turn it off and on again, sometimes this helps with strange hardware issues… :wink:

I think you should try a different router though, if possible.
Or maybe a firmware update would help?

5

This router belongs to Verizon. I will try the reboot route on the router to see if it helps. Apparently, I have the latest firmware. Is there any preferred brand if I decide to buy a different router?

6

Sorry, I cannot really help you there. But I guess the brand shouldn’t matter much.

Anyway, I’m not at all sure that the router is the problem, that’s just guessing. So I would just take some cheap one, maybe second-hand, for a try.

7

So, we’re talking about a modem-router. According to a tech friend just unplugging and restarting it is not enough, you need to keep the power off for at least 1 minute, 5 minutes is better. Also, the power needs to be off completely, so unplug. In my case (some urls couldn’t be pinged by domainname, others not by ip, I had already reset the modemrouter) this worked perfectly, so nothing “inside” was wrong or broken.
BTW At a customer’s I had to reset a router to factory defaults to get it back to work, this with exactly the same settings it had when it failed.

8

As suggested, I unplugged the router for a while; several minutes. I have been running for some days without issue. So, the issue is resolved, even if I don’t know what it was. Thank you.

9

I spoke too soon. Minutes after posting, I did zypper up and a reboot. Could no longer connect to the internet, getting “network is unreachable” message when I tried to ping the router. However, I was able to get a usb wireless dongle to connect. Thinking there may be a hardware problem, I installed an old network card, which also has worked although I have not tried to see if it survives a reboot.

When I run

systemctl status network.service -l

part of the message says it fails to find ethbus-pcmcia. I said the original ethernet connection (built in to the motherboard) was ethbus-pcmcia in an effort to get something to work. Now, I don’t see how to eliminate it. At one time, I changed the name of the built-in from enp8s2 to eth0. I tried removing this “card” via yast but it would not restore the former name. When I installed the ethernet card, yast gave it the name enp8s4.

There has to be a setting somewhere that I can change, or a file to delete, that would sort this out. I’m afraid to reboot anymore.

10

The latest update to sysconfig-network contains a logical error which breaks starting interfaces “on cable-connect”. Sounds like you encountered this.
If you set them to start “on boot” in YaST->Network Settings->Network Devices, they should work.

When I run

systemctl status network.service -l

part of the message says it fails to find ethbus-pcmcia. I said the original ethernet connection (built in to the motherboard) was ethbus-pcmcia in an effort to get something to work. Now, I don’t see how to eliminate it.

Where did you to that? In YaST? Then you should be able to revert it there again.

At one time, I changed the name of the built-in from enp8s2 to eth0. I tried removing this “card” via yast but it would not restore the former name. When I installed the ethernet card, yast gave it the name enp8s4.

There has to be a setting somewhere that I can change, or a file to delete, that would sort this out. I’m afraid to reboot anymore.

The interface name rules are stored in the file /etc/udev/rules.d/70-persistent-net.rules, and the interface settings are stored in /etc/sysconfig/network/ in files that are called ifcfg-${INTERFACE}.
Remove the ones that don’t exist.
Or remove all and reconfigure the interface(s) with YaST.

11

I have 3 devices listed in yast–>network settings–>overview
the first is built-in ethernet adapter and it is not configured (I did that to prevent a conflict.)
the second is the wireless dongle which has a long device name, not wlan0. It is set to connect on boot. I do not have it plugged in at the moment.
the last is the old card I installed. It has a long device name too, not eth0, and is set for connect on boot.

Looking at /etc/udev/rules.d/70-persistent-net.rules, the only device listed is eth0, which once was the built-in adapter that I “de-configured.”

Looking at the ifcfg files, I see files for the card and wireless but no eth0. There is a ethbus-pcmcia file. I will become root and delete this.

I will update and reboot for the first time in days. Hope the connection survives!

12

What conflict?

Looking at /etc/udev/rules.d/70-persistent-net.rules, the only device listed is eth0, which once was the built-in adapter that I “de-configured.”
That’s because you only manually assigned the name “eth0” to one of the cards. The others get their name automatically by udev.
Looking at the ifcfg files, I see files for the card and wireless but no eth0. There is a ethbus-pcmcia file. I will become root and delete this.
So eth0 is not configured. If you wanted to use that, you have to configure it first. The other one is and should work. But better check that it is set to start “on boot”, as “on cable-connect” does not work at the moment.

13

I was afraid of having two ethernet cards connected at once, so I “de-configured” the built-in card to avoid a conflict with the card I installed to overcome this problem.

I rebooted to see if the network connection would survive a reboot. It did not. Once I tested that, I deleted the file ifcfg-ethbus-pcmcia since there is no such device. I rebooted again to see what would happen and after 10-20 seconds, it automatically connected to the network and ultimately to the internet. Remember, the problem surfaced before I had somehow created that ethbus-pcmcia file. I am now guessing that the built-in ethernet has a hardware problem which I complicated by creating that ethbus file.

Thanks wolfi323 for sticking with this. I hope I’m done with this.

14

There is no conflict when you have two (or more) network cards.

But in earlier versions it could have happened that when you plugged in a new network card (and no 70-persistent-net-rules file was present), that the new one would get “eth0” assigned and the old “eth0” would suddenly be called “eth1”.
That’s why those “persistent names” (“enp0s2”, “enp8s2”, and so on) got invented.

Remember, the problem surfaced before I had somehow created that ethbus-pcmcia file. I am now guessing that the built-in ethernet has a hardware problem which I complicated by creating that ethbus file.

But before that the router was having problems, wasn’t it?

You should be able to just try out your built-in card again. Configuring it should have no impact on the other connections (as long as there’s no cable connected at least).

Thanks wolfi323 for sticking with this. I hope I’m done with this.

Yeah. I hope so as well… :wink: