Unlike IPv4 dhcpd log messages, IPv6 dhcpd log messages come with no client hostname (OPTION 39). After trying to use lookup_option() in dhcpv6.c like bellow: oc = lookup_option(&dhcpv6_universe, packet->options, D6O_CLIENT_FQDN); Tests shows it won't work. Is there a way to lookup client hostname? -- yc.