I am running 18.06 OpenWRT for one month now. One of the attached devices is a Rapsberry PI3 with Arch linux.
In the log I see an "NDISC: Received Router Advertisement", every 8 minutes. It says 'valid forever' but it still sends updates.
See log below. Is this normal?
Jan 05 21:06:24 RPI3 systemd-networkd[346]: NDISC: Received Router Advertisement: flags MANAGED preference medium lifetime 0 sec
Jan 05 21:06:24 RPI3 systemd-networkd[346]: NDISC: Invoking callback for 'r'.
Jan 05 21:06:24 RPI3 systemd-networkd[346]: eth0: Acquiring DHCPv6 lease on NDisc request
Jan 05 21:06:24 RPI3 systemd-networkd[346]: eth0: Updating address: fd8a:ba7c:bdad:0:ba27:ebff:fe81:9a46/64 (valid forever)
Jan 05 21:10:02 RPI3 kernel: audit: type=1006 audit(1546719002.133:73): pid=1232 uid=0 old-auid=4294967295 auid=0 tty=(none) old-ses=4294967295 ses=7 res=1
...
Jan 05 21:14:27 RPI3 systemd-networkd[346]: NDISC: Received Router Advertisement: flags MANAGED preference medium lifetime 0 sec
Jan 05 21:14:27 RPI3 systemd-networkd[346]: NDISC: Invoking callback for 'r'.
Jan 05 21:14:27 RPI3 systemd-networkd[346]: eth0: Acquiring DHCPv6 lease on NDisc request
Jan 05 21:14:27 RPI3 systemd-networkd[346]: eth0: Updating address: fd8a:ba7c:bdad:0:ba27:ebff:fe81:9a46/64 (valid forever)