On Wed 27 Apr 2022 at 22:49:59 (+0200), nimrod wrote: > > yesterday afternoon, after working all day at office without any > (network) problem, I decided to reboot my machine. Suddenly I could not > navigate on the web. But I could ping the gateway, I could resolve > names... just cannot reach the network (most commands just issued the > classic "network is unreachable" message). > > thinking it was a route problem, I issued "ip route" on the terminal > and got this default route: > > default dev eno1 scope link src 169.254.30.62 metric 202 > > I deleted it and add the good one: > > ip route add default via 192.168.1.113 dev eno1 > > and I could navigate again immediately. Nevertheless, after every > reboot the wrong default route is there again. I couldn't find any file > or directory in which this could be configured, nor I found a command > that could create somehow implicitly such a default route. > > How can prevent it to come back after reboot? I could add some kind of > /etc/rc.local or a systemd target to remove the wrong one and add the > right one at every boot, but i would prefer to understand why it > happens. At least, since a 169.254 route is always on, I wish to > undestand why it becomes the default one, preventing me from reach the > internet. > > Please note that I only use Network Manager from the Gnome GUI with a > static address, and I didn't modify the configuration in several > months. Never touched /etc/network* dirs and files, nor > /etc/systemd/network.
It sounds as if your computer failed to find the DHCP server when you rebooted "yesterday" afternoon, which could have made it autoconfigure the interface with 169.254 (called ?mDNS), and add a route. There doesn't seem to be a problem having these interfaces around unless they get a default route. I would look in /var/lib/avahi-autoipd/ and see if there's a file called <your-eno1's-MAC> containing 169.254.30.62. If so, remove it and, next time you reboot, it shouldn't happen. (That is, unless you have a recurrence of the same problem as "yesterday" afternoon.) I can simulate the same effect on a laptop by tapping its rfkill switch when it boots, preventing the wifi from configuring. Because /e/n/i still has a DHCP ethernet configuration festering there as well as the wifi one, it sets an ethernet route that obstructs the wifi's getting one when I un-rfkill the wifi. As for the original cause, take a look at /var/log/daemon.log* for "yesterday" afternoon with zgrep -i -e dhcp -e dhclient Cheers, David.
