I have a desktop computer running Slackware current and am using CenturyLink DSL. I am using NetworkManager. Sometimes the Internet Connection quits, and I am not able to start it up again without rebooting. I tried entering the following in a terminal:

su
cd /etc/rc.d
rc.networkmanager stop
rc.M restart

I also tried "rc.networkmanager restart", and "rc.inetd restart". I still couldn't get the Internet connection restarted that way. Even though at the same time I can get wireless internet working on my laptop which also runs Slackware current with the same DSL provider. When I enter "dhcpcd" in a terminal running as root, I will get the following entry when I can't get the connection going without rebooting.

dhcpcd[15157]: version 6.0.5 starting
dhcpcd[15157]: eth0: soliciting an IPv6 router
dhcpcd[15157]: eth0: rebinding lease of 192.168.0.2
dhcpcd[15157]: eth0: soliciting a DHCP lease
dhcpcd[15157]: eth0: no IPv6 Routers available
dhcpcd[15157]: timed out
dhcpcd[15157]: allowing 8 seconds for IPv4LL timeout
dhcpcd[15157]: eth0: probing for an IPv4LL address
dhcpcd[15157]: timed out
dhcpcd[15157]: forked to background, child pid 15190

I also had this problem when I had Slackware 14. I didn't notice the problem for the month that I ran Siduction with systemd. I would like to keep my desktop on Slackware, but don't want to have to reboot every time I get this connection dropped.

If you're losing IPv4 then it might not be Slackware or dhcpcd, dhcp, or networkmanager. Sometimes certain network cards have a time-out feature built-in that could be activated. When systemctl saw the network daemon die, it relaunched it's networking stack which revived the device.

Don't forget to try and restart rc.netdevice also. That's the main network driver controller script.

You could be also experiencing the first symptoms of a faulty network device if this restarting restores the network stack. I would test with a different PC or NIC if possible. If the network doesn't die then you'll have your answer. If it does, check your CenturyLink Router options for DHCP lease time and set it to the maximum allowable time.

Thanks for posting ReaperX7.
I did reset the DHCP maximum lease time to 365 days which is close to the maximum allowable time. So, far I have not had a dropped connection since I started this thread, other than on 10/21 on which I successfully got it going by closing networkmanager and starting dhcpcd in a terminal. After, doing a search using Strigi and Dolphin, I discovered I do not have the rc.netdevice script. It is not on the default installation of Slackware 14.1, and is also not available on current, unless the user adds such a script. I will continue to see if lengthening the maximum lease time will let me continue to have an internet connection without rebooting, or running an application that performs the function of the rc.netdevice script.