======kea_cfg_opt15======
Example of configuration for option 15 (''dhcp6_poolname_opt=1'') for Kea DHCPv6:
<code bash>
  # Class Description
  "client-classes": [
    { # opt15 User-Class 
        "name": "ppp_userclass_ip6_pool",
        "test": "substring( option[15].hex, 2, 100 ) == 'ppp_userclass_ip6_pool'",
	    # In option-data you can set options common to this class
            "option-data": [
                {
                    "name": "dns-servers",
                    "space": "dhcp6",
                    "data": "2001:db8:2::dead:cafe, 2001:db8:2::cafe:dead"
                }
            ]
    },
    # Description of other classes
    # ...
  ] # end of client-classes 

  # Setting pools
  "shared-networks": [
    {
    "name": "MyNetworks",

    # The pools are accessed on behalf of the relay
    "relay": {
        "ip-addresses": ["2001::1"]
    },

    "subnet6": [
        {
            "client-class": "ppp_userclass_ip6_pool",
            "subnet": "2a02:400:1::/48",

            # IMPORTANT! Only a PD prefix with a length one less than the value of the 
            # of the ipv6_subnetmask parameter in fastdpi.conf (default value is 64).
            # SCAT itself splits this prefix into 2 ipv6_subnetmask lengths: the younger one
            # /64 subnet is given to the client, the older one is under the client prefix
            "pd-pools": [
                    {
                    "prefix": "2a02:400:1::",
                    "prefix-len":48,
                    "delegated-len": 63
                    }
            ]
        }

        # description of other pools
        # ...
    ] # end of subnet6
  ] # end of shared-networks

</code>