When using check_ping to check a dual-stacked website (e.g. www.heise.de) from a host that has IPv6 enabled but no global IPv6 address check_ping will fail (Network unreachable).
Please consider implementing RFC 6724 (Default Address Selection for Internet Protocol Version 6 (IPv6)) for check_ping. -- Reply to this email on GitHub: https://github.com/monitoring-plugins/monitoring-plugins/issues/1397
