eth0 doesn't work on new slackware 14.2 installation
 

Hi,

Just finished to install slackware but the network doesn't work.
At boot time, I have a message "eth0: no carrier". I tried to configure the network with KDE Network Manager, I can't even add a new wired connection. ifconfig says the interface is UP but no IPv4 information.
The network works well with w10 on this machine.

Thanks in advance,

add manually an address to eth0 (192.168.0.100), I can only ping the self address. Any ping on other hosts on the subnet results in "Destination host unreachable".

Can you post the output of the following commands?

@odjb
Since you've excluded the cable connection (link) by saying that it works under W10, then it might be caused by the "aggressive" power management of the PCI controller, especially if it's a new laptop (new Intel CPU/chipset).
Check the status of the device by issuing what bassmadrigal suggested:
-or simple:
and look for your network adapter PCI address - the first digits before the name/description (Ethernet controller) in the form: XX:XX:X
Then check the power status of the device:
If it's on auto then it might be well suspended and you can bring it up with the following:
If it works, then put the last line in the beginning of your /etc/rc.d/rc.inet1 script for the next boot(s).

Below the results from asked actions. I go check the power managament

ok, checked the power management, it's already "on"

Based on the quoted output, I'm wondering if you forgot to set up your networking during the install. I've never seen this error before, but you shouldn't need to declare anything in your dhcpcd.conf like it states if you are using Slackware's rc.inet scripts. To ensure those scripts are set up properly, run netconfig as root and first select loopback to reset any possible problems, then run it again and set it up for DHCP. Once that's done, either reboot or run /etc/rc.d/rc.inet1 restart and see if you get internet access.

I tried but it didn't work (in fact I already did it before)
Let me post an extract from boot messages regarding the network :

@odjb

The Realtek r8169 driver looks to be problematic (kernel related and not Slackware related) and apparently you'll need to turn the autonegotiation off with the help of ethtool before bringing the interface up and trying to obtain an IP address with dhcpd/dhclient:
As previously advised, put these lines in the very beginning of your /etc/rc.d/rc.inet1 script, before any network definitions, in order to have a permanent fix.
References:
https://forums.fedoraforum.org/showthread.php?t=250807
https://askubuntu.com/questions/7610...8169-link-down
http://adam.rosi-kessel.org/weblog/2...k-down-problem

@odjb

Have you got it working? Please report / set the thread to RESOLVED if that's the case.

It didn't work. I stop eth0, set autoneg off. I see autoneg is actually off. I restart eth0. autoneg is on again and the network still doesn't work.

@odjb

Try not to stop it (bring it down) but while on (up) only change the autonegotiation with:
Check if it's tuning it on off and then try a dhcpd/dhclient on it.

There were reports that the r8169 Linux driver doesn't support gigabit on the adapter and additionally to disabling the autonegotiation you need to tune it to 100Mbit. To do this, execute:
You could take a different approach, tune the autoneg on off while loading the driver, like described here:
https://forums.fedoraforum.org/showp...07&postcount=1
On the latest Slackware you need to define the r8169.conf in the /lib/modprobe.d/ directory like this:
Content of /lib/modprobe.d/r8169.conf
Then reboot the system and check if it's working / autoneg stays deactivated.

Here is even suggested to blacklist the r8169 driver and use the r8168 instead:
https://askubuntu.com/questions/7610...8169-link-down

You could also check the driver options with:
look for "parm:" and maybe you have some driver parameters you could tune in /lib/modprobe.d/r8169.conf
with:
(substitute your_option with the appropriate option (autoneg/speed/etc.) you get in the parm: section from modinfo)
restart the system and check the functionality.

I tried the following without stopping eth0 and it worked.
I didn't have time to tune the driver but at last, the network worked. I think it's a pity that I can't use the network card at 1gb so maybe I will purchase another card later. ASAP, I try to add the modification so it can boot in the correct state and I will mark the post as solved.

Thanks

@objb
Happy to hear that you've got it working. You should follow the history on the development of the r8169 driver, maybe it'll get fixed in the following kernel releases.
https://github.com/torvalds/linux/co...ealtek/r8169.c

@odjb
I just recalled that your NIC isn't really working well with the ethtool workaround and considered that you might want to try the r8168 driver and blacklist the r8169.
Check this thread for the instructions on where to get and compile the driver:
https://www.linuxquestions.org/quest...7/#post5784210
Posts:10-14

After the compilation & installation of the r8168 run the following (comment your ethtool workaround command if you inserted it into /etc/rc.d/rc.inet1):
If the above is working - then go for a permanent fix:
-create a file /lib/modprobe.d/blacklist-r8169.conf with the following content:
- comment your ethtool command if you have inserted it into some startup script:
- reboot your computer and check if the NIC/r8168 driver are happy

Wait (check from time to time) for a r8169 driver fix in newer kernels.