default-lease-time 640;
max-lease-time 700;
log-facility local7;

subnet6 2011:1:2::/48 {

        # Range for clients
        range6 2011:1:2::111 2011:1:2::234;

        # Additional options
        option dhcp6.name-servers 2011:1:2::2012;
        option dhcp6.domain-search "ipv6.domain.example";

        # Prefix range for delegation to sub-routers
          prefix6 2011:1:2:2:: 2011:1:2:2:: /64;

       # Example for a fixed host address
        host specialclient {
                host-identifier option dhcp6.client-id 00:01:00:01:4a:1f:ba:e3:60:b9:1f:01:23:45;
                fixed-address6 2011:1:2::110;
        }
}

root@reed-Lenovo:/etc/dhcp# /root/dhcp-4.3.4/server/dhcpd -6 -d -cf /etc/dhcp/dhcpd6.conf eth0
Internet Systems Consortium DHCP Server 4.3.4
Copyright 2004-2016 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
WARNING: Host declarations are global.  They are not limited to the scope you declared them in.
Config file: /etc/dhcp/dhcpd6.conf
Database file: /var/db/dhcpd6.leases
PID file: /var/run/dhcpd6.pid
Wrote 0 deleted host decls to leases file.
Wrote 0 new dynamic host decls to leases file.
Wrote 0 NA, 0 TA, 1 PD leases to lease file.
Bound to *:547
Listening on Socket/5/eth0/2011:1:2::/48
Sending on   Socket/5/eth0/2011:1:2::/48
Server starting service.
Solicit message from fe80::3291:8fff:fe05:bf86 port 546, transaction ID 0xF5FFA00
Advertise PD: address 2011:1:2:2::/64 to client with duid 00:03:00:01:30:91:8f:05:bf:86 iaid = 1 valid for 640 seconds
Sending Advertise to fe80::3291:8fff:fe05:bf86 port 546
Request message from fe80::3291:8fff:fe05:bf86 port 546, transaction ID 0x936B200
Reply PD: address 2011:1:2:2::/64 to client with duid 00:03:00:01:30:91:8f:05:bf:86 iaid = 1 valid for 640 seconds
Sending Reply to fe80::3291:8fff:fe05:bf86 port 546