Not sure if this will overlap with anyone else, but my experience was a combination of 2 things:
1. Reboots were happening, caused by unattended-upgrade 2. The device causing trouble was a renamed device. Turns out it was trying to get renamed twice: Once very early in boot from eth1 to eno2, then again based on my neplan from eno2 to the name I wanted. This was failing, and leaving the device down. See my comment #117 on this issue for more details: https://bugs.launchpad.net/netplan/+bug/1770082 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1775131 Title: Ubuntu 18.04 networking issue (connection drops after approx. 15 minutes) Status in linux package in Ubuntu: Confirmed Bug description: I'm currently troubleshooting some network issues on Ubuntu 18.04 LTS Bionic. After checking a few logs I noticed that the networkd-dispatcher is generating errors. I'm unsure if this is a bug but I'd like to report it over here just to be sure: ``` Jun 04 18:14:21 [servername] systemd-networkd-wait-online[2079]: managing: br2 Jun 04 18:14:22 [servername] networkd-dispatcher[1890]: WARNING:Unknown index 7 seen, reloading interface list Jun 04 18:14:23 [servername] networkd-dispatcher[1890]: WARNING:Unknown index 8 seen, reloading interface list Jun 04 18:14:23 [servername] networkd-dispatcher[1890]: ERROR:Unknown interface index 8 seen even after reload Jun 04 18:14:23 [servername] networkd-dispatcher[1890]: WARNING:Unknown index 8 seen, reloading interface list Jun 04 18:14:23 [servername] networkd-dispatcher[1890]: ERROR:Unknown interface index 8 seen even after reload ``` These issues occur consistently on several servers. The problem is that I lose the connection specifically towards the internet after approx. 15 minutes. Internal facing interfaces (same hardware and driver) seem to behave differently and remain properly connected to the internal network. These network-dispatcher errors seem to occur simultanously when the connection on the external interface permanently drops. The physical network links still appears to be online when the connection is lost. I'm still also able to ping the default gateway from my provider to access the Internet. But all IP addresses beyond this gateway on the Internet seem to be unreachable. I have disabled TCP offloading and firewalls to eliminate any influences. But that didn't work. The ARP table shows that my gateway is a STALE record after the connection drops. So it seems related to the ARP-table or something likewise. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1775131/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
