Wikipedia:Reference desk/Archives/Computing/2016 May 15

= May 15 =

Internet stopped working after upgrade from Fedora 20 to Fedora 23
I recently upgraded from Fedora 20 to Fedora 23. I installed Fedora 23 on a fresh drive and kept my old drive as a backup.

Now I cannot connect to the Internet on Fedora 23. This happens regardless of whether I use the live media or the actual installation. I just cannot contact any server.

What is strange that using the old Fedora 20 installation, the Internet works all OK. It's the same computer with the same hardware and network cable, I just changed to a different OS on a different disk.I even have the exact same network connection configuration on both installations, right down to identical IP4 address, IP6 address and MAC address.

Actually, the Internet connection on the new Fedora 23 installation sometimes sporadically works, but very slowly. Most of the time it just doesn't work. And all this time the Internet connection on the old Fedora 20 installation works all OK. It's the exact same physical connection, only the OS is different.

Does anyone have any idea what is happening here and how to fix this? J I P &#124; Talk 18:10, 15 May 2016 (UTC)
 * Re-check your assumptions. A simple thing as keeping the IP when the connection router has changed it's own may mess up the connection. But anyway, ping 127.0.0.1 to verify local stack. Then ping your own external IP. Check netmask, router-IP, traceroute, setup at the gateway/router, DHCP handling, etc. Bytesock (talk) 18:33, 15 May 2016 (UTC)


 * What are you using for your physical network device? I had a USB wireless connector that worked in Fedora 20. By Fedora 22, the driver didn't work and there were (and still are) no options to make the device work. I had to switch to a different USB wireless connector. The issue was that I was using the NDIS driver for the previous device and NDIS simply doesn't work anymore. So, I had to switch to one with a native Linux driver. 209.149.114.175 (talk) 12:34, 16 May 2016 (UTC)


 * I have a "AR8161 Gigabit Ethernet" network device, according to lshw. It turns out the Linux kernel 4.2 drivers for it have a bug that causes communications to drop using the default MTU value. I increased the MTU value to 9000 and now I can at least connect to the Internet and browse webpages. Apparently it should be fixed in kernel 4.5, but I don't have that version yet. J I P  &#124; Talk 15:30, 16 May 2016 (UTC)