Additional logs:
Sep 24 12:32:23 r1-roll systemd[1]: Starting NDP Proxy Daemon... Sep 24 12:32:23 r1-roll ndppd[2150]: (notice) ndppd (NDP Proxy Daemon) version 0.2.4 Sep 24 12:32:23 r1-roll ndppd[2150]: (notice) Using configuration file '/run/ndppd/ndppd.conf' Sep 24 12:32:23 r1-roll ndppd[2150]: (warning) Low prefix length (80 <= 120) when using 'static' method Sep 24 12:32:23 r1-roll ndppd[2150]: (warning) Low prefix length (80 <= 120) when using 'static' method Sep 24 12:32:23 r1-roll systemd[1]: ndppd.service: Can't open PID file /run/ndppd/ndppd.pid (yet?) after start: Operation not permitted Sep 24 12:32:23 r1-roll kernel: [ 131.465473] NET: Registered protocol family 17 Sep 24 12:32:23 r1-roll isisd[1006]: circuit already connected