SOLVED - NDISC received router advertisement - every 8 minutes - is this normal

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)

Router advertisements, or RAs, are normal (and pretty much essential) for operation on an IPv6-enabled subnet.

https://tools.ietf.org/html/rfc4861 suggests

      MaxRtrAdvInterval
                     The maximum time allowed between sending
                     unsolicited multicast Router Advertisements from
                     the interface, in seconds.  MUST be no less than 4
                     seconds and no greater than 1800 seconds.

                     Default: 600 seconds

so every 480 seconds or so is well within the guidelines.

1 Like

Thanks for you clear answer!!

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