odhcpd: excessive logging of RA lifetime

Username: Paul Traina

Origin: https://bugs.openwrt.org/index.php?do=details&task_id=1628

This is master as of June 29th, 2018.

Enable and run ohdpcd on a few lan interfaces...

Mon Jul 2 22:25:28 2018 daemon.info odhcpd[1139]: Using a RA lifetime of 1800 seconds on br-lan

Mon Jul 2 22:25:28 2018 daemon.info odhcpd[1139]: Using a RA lifetime of 1800 seconds on br-guest

Mon Jul 2 22:25:38 2018 daemon.info odhcpd[1139]: Using a RA lifetime of 1800 seconds on br-lan

Mon Jul 2 22:25:38 2018 daemon.info odhcpd[1139]: Using a RA lifetime of 1800 seconds on br-guest

Mon Jul 2 22:25:42 2018 daemon.info odhcpd[1139]: Using a RA lifetime of 1800 seconds on br-lan

Mon Jul 2 22:25:42 2018 daemon.info odhcpd[1139]: Using a RA lifetime of 1800 seconds on br-guest

Should not be repeating, should not be at daemon.info either. Don’t pollute the log if nothing has changed.