3.8. Classifying clients in Kea

Procedure

1. If you are configuring an IPv4 network:

   1. Edit the /etc/kea/kea-dhcp4.conf file, and make the following changes:

      1. Add the following client classes to the Dhcp4 parameter:

         {
           "Dhcp4": {
             ...
             "client-classes": [
               {
                   "name": "VoIP-Phones",
                   "test": "substring(pkt4.mac, 0, 3) == 0x525400"
               },
               {
                   "name": "Others",
                   "test": "not member('VoIP-Phones')"
               }
             ],
             ...

         In this example, devices with a MAC address starting with 52:54:00 match the VoIP-Phones client class. Devices that do not match the rule are assigned to the Others client class.

      2. Assign the client classes to your pool definitions:

         {
           "Dhcp4": {
             "subnet4": [
               {
                 "subnet": "192.0.2.0/24",
         	"pools": [
                   {
                     "pool": "192.0.2.20  - 192.0.2.100",
                     "client-class": "Others"
                   },
                   {
                     "pool": "192.0.2.150 - 192.0.2.200",
                     "client-class": "VoIP-Phones"
                   }
                 ],
                 ...

         Depending on which client class a host matches, Kea assigns an IP from the corresponding pool.

   2. Verify the syntax of the configuration file:

      # kea-dhcp4 -t /etc/kea/kea-dhcp4.conf

      If the command returns Syntax check failed, fix the errors shown in the report.

   3. Restart the kea-dhcp4 service:

      # systemctl restart kea-dhcp4

2. If you are configuring an IPv6 network:

   1. Edit the /etc/kea/kea-dhcp6.conf file, and make the following changes:

      1. Add the following client classes to the Dhcp6 parameter:

         {
           "Dhcp6": {
             ...
             "client-classes": [
               {
                   "name": "VoIP-Phones",
                   "test": "option[16].exists and (substring(option[16].hex, 0, 8) == '00000009')",
               },
               {
                   "name": "Others",
                   "test": "not member('VoIP-Phones')"
               }
             ],
             ...

         In this example, devices that send a DHCPv6 vendor class option (option 16) where the hexadecimal value begins with 00000009 match the VoIP-Phones client class. Devices that do not match the rule are assigned to the Others client class.

      2. Assign the client classes to your pool definitions:

         {
           "Dhcp6": {
             "subnet6": [
               {
                 "subnet": "2001:db8:0:1::/64",
         	"pools": [
                   {
                     "pool": "2001:db8:0:1::1000 - 2001:db8:0:1::2000",
                     "client-class": "Others"
                   },
                   {
                     "pool": "2001:db8:0:1::4000 - 2001:db8:0:1::5000",
                     "client-class": "VoIP-Phones"
                   }
                 ],
                 ...

         Depending on which client class a host matches, Kea assigns an IP from the corresponding pool.

   2. Verify the syntax of the configuration file:

      # kea-dhcp6 -t /etc/kea/kea-dhcp6.conf

      If the command returns Syntax check failed, fix the errors shown in the report.

   3. Restart the kea-dhcp6 service:

      # systemctl restart kea-dhcp6