Where 2803:1920:0:1::/64 is the WAN ONU, then the network connection ONU and OLT.

== /etc/dhcp/dhcpd.conf ==

  subnet6 2803:1920:0:1::/64 {
      option dhcp6.name-servers 2803:1920:0:1::1, 2001:4860:4860::8888;
  
      host test{
          hardware ethernet 80:14:a8:5f:32:e4;
          fixed-address6 2803:1920:0:1::3;
          fixed-prefix6 2803:1920:0:2ff::/64;
      }
  
      host test2{
          hardware ethernet 80:14:a8:87:d2:15;
          fixed-address6 2803:1920:0:1::4;
          fixed-prefix6 2803:1920:0:1ff::/64;
      }
  }
  
== /etc/radvd.conf ==
  interface eth1
  {
      AdvSendAdvert on;
      AdvDefaultPreference medium;
      AdvSourceLLAddress on;
      # Advertise at least every 30 seconds
      MaxRtrAdvInterval 30;
      AdvLinkMTU 1280;
      AdvManagedFlag on;
      AdvLinkMTU 1480;
      AdvOtherConfigFlag on;
      MinRtrAdvInterval 3;
      
      prefix 2803:1920:0:1:0:0:0:0/112
      {
        AdvOnLink on;
        AdvAutonomous on;
        AdvRouterAddr on;
      };
  };