Serveur DHCP Kea 3.0.2

Fichiers de configuration

/etc/kea/keactrl.conf, /etc/kea/kea-ctrl-agent.conf, /etc/kea/kea-dhcp4.conf, /etc/kea/kea-dhcp6.conf et /etc/kea/kea-dhcp-ddns.conf

Configuration du contrôleur de Kea

keactrl is used to control the independent servers (IPv4, IPv6, DDNS). Its configuration file, /etc/kea/keactrl.conf, is installed by default and includes many path settings which are defined from the configure at build time. It also includes settings to specify which of the servers should be started.

The Netconf service is not installed because the required dependencies are not installed by BLFS, and configuring it correctly is complicated.

With the following command, Kea will be configured to start the DHCP service for IPv4 and the dynamic DNS update, while the control agent and the DHCP service for IPv6 remain down. Tweak the command to match your needs on started services and execute as the root user:

sed -e "s/^dhcp4=.*/dhcp4=yes/" \
    -e "s/^dhcp6=.*/dhcp6=no/" \
    -e "s/^dhcp_ddns=.*/dhcp_ddns=yes/" \
    -e "s/^ctrl_agent=.*/ctrl_agent=no/" \
    -i /etc/kea/keactrl.conf

Configuration de l'agent de contrôle

The provided configuration could be used without changes. However, in BLFS, objects like sockets are stored in /run rather than in /tmp.

cat > /etc/kea/kea-ctrl-agent.conf << "EOF"
// Begin /etc/kea/kea-ctrl-agent.conf
{
  // This is a basic configuration for the Kea Control Agent.
  // The RESTful interface will be available at http://127.0.0.1:8000/
  "Control-agent": {
    "http-host": "127.0.0.1",
    "http-port": 8000,
    "control-sockets": {
      "dhcp4": {
        "socket-type": "unix",
        "socket-name": "/run/kea/kea4-ctrl-socket"
      },
      "dhcp6": {
        "socket-type": "unix",
        "socket-name": "/run/kea/kea6-ctrl-socket"
      },
      "d2": {
        "socket-type": "unix",
        "socket-name": "/run/kea/kea-ddns-ctrl-socket"
      }
    },

    "loggers": [
      {
        "name": "kea-ctrl-agent",
        "output_options": [
          {
            "output": "/var/log/kea/kea-ctrl-agent.log",
            "pattern": "%D{%Y-%m-%d %H:%M:%S.%q} %-5p %m\n"
          }
        ],
        "severity": "INFO",
        "debuglevel": 0
      }
    ]
  }
}
// End /etc/kea/kea-ctrl-agent.conf
EOF

Configuration du serveur DHCP IPv4

A sample configuration file is created in /etc/kea/kea-dhcp4.conf. Adjust the file to suit your needs or overwrite it by running the following command as the root user (you'll need to edit this file anyway: at least the interfaces field, the ddns-qualifying-suffix field, and almost all the fields in Subnet4):

cat > /etc/kea/kea-dhcp4.conf << "EOF"
// Begin /etc/kea/kea-dhcp4.conf
{
  "Dhcp4": {
    // Add names of your network interfaces to listen on.
    "interfaces-config": {
      "interfaces": [ "eth0", "eth2" ]
    },

    "control-socket": {
      "socket-type": "unix",
      "socket-name": "/run/kea/kea4-ctrl-socket"
    },

    "lease-database": {
      "type": "memfile",
      "lfc-interval": 3600,
      "name": "/var/lib/kea/kea-leases4.csv"
    },

    "expired-leases-processing": {
      "reclaim-timer-wait-time": 10,
      "flush-reclaimed-timer-wait-time": 25,
      "hold-reclaimed-time": 3600,
      "max-reclaim-leases": 100,
      "max-reclaim-time": 250,
      "unwarned-reclaim-cycles": 5
    },

    "renew-timer": 900,
    "rebind-timer": 1800,
    "valid-lifetime": 3600,

    // Enable DDNS - Kea will dynamically update the BIND DNS server
    "ddns-send-updates" : true,
    "ddns-qualifying-suffix": "your.domain.tld",
    "dhcp-ddns" : {
      "enable-updates": true
    },

    "subnet4": [
      {
        "id": 1001,   // Each subnet requires a unique numeric id
        "subnet": "192.168.56.0/24",
        "pools": [ { "pool": "192.168.56.16 - 192.168.56.254" } ],
        "option-data": [
          {
            "name": "domain-name",
            "data": "your.domain.tld"
          },
          {
            "name": "domain-name-servers",
            "data": "192.168.56.2, 192.168.3.7"
          },
          {
            "name": "domain-search",
            "data": "your.domain.tld"
          },
          {
            "name": "routers",
            "data": "192.168.56.2"
          }
        ]
      }
    ],

    "loggers": [
      {
        "name": "kea-dhcp4",
        "output_options": [
          {
            "output": "/var/log/kea/kea-dhcp4.log",
            "pattern": "%D{%Y-%m-%d %H:%M:%S.%q} %-5p %m\n"
          }
        ],
        "severity": "INFO",
        "debuglevel": 0
      }
    ]
  }
}
// End /etc/kea/kea-dhcp4.conf
EOF

Configuration du serveur DHCP IPv6

La configuration pour l'IPv6 est similaire à la configuration pour l'IPv4. Le fichier de configuration est /etc/kea/kea-dhcp6.conf.

Configuration du DNS dynamique

If there is a BIND-9.20.16 server running, ISC Kea can update the DNS records when it gives an IP address to a client. A sample configuration file is created in /etc/kea/kea-dhcp-ddns.conf. Adjust the file to suit your needs or overwrite it by running the following command as the root user:

cat > /etc/kea/kea-dhcp-ddns.conf << "EOF"
// Begin /etc/kea/kea-dhcp-ddns.conf
{
  "DhcpDdns": {
    "ip-address": "127.0.0.1",
    "port": 53001,
    "control-socket": {
      "socket-type": "unix",
      "socket-name": "/run/kea/kea-ddns-ctrl-socket"
    },

    "tsig-keys": [
      {
        "name"      : "rndc-key",
        "algorithm" : "hmac-sha256",
        "secret"    : "1FU5hD7faYaajQCjSdA54JkTPQxbbPrRnzOKqHcD9cM="
      }
    ],

    "forward-ddns" : {
      "ddns-domains" : [
        {
          "name" : "your.domain.tld.",
          "key-name": "rndc-key",
          "dns-servers" : [
            {
              "ip-address" : "127.0.0.1",
              "port" : 53
            }
          ]
        }
      ]
    },

    "reverse-ddns" : {
      "ddns-domains" : [
        {
          "name" : "56.168.192.in-addr.arpa.",
          "key-name": "rndc-key",
          "dns-servers" : [
            {
              "ip-address" : "127.0.0.1",
              "port" : 53
            }
          ]
        }
      ]
    },

    "loggers": [
      {
        "name": "kea-dhcp-ddns",
        "output_options": [
          {
            "output": "/var/log/kea/kea-ddns.log",
            "pattern": "%D{%Y-%m-%d %H:%M:%S.%q} %-5p %m\n"
          }
        ],
        "severity": "INFO",
        "debuglevel": 0
      }
    ]
  }
}
// End /etc/kea/kea-dhcp-ddns.conf
EOF

Note

La valeur de secret n'est qu'un exemple. Générez la clé pour votre installation en exécutant la commande rndc-confgen -a ou la commande tsig-keygen qui sont toutes deux fournies par BIND-9.20.16.

Dans cette configuration d'exemple nous supposons que le serveur DNS tourne sur la même machine que Kea (accessible via 127.0.0.1) et que cette machine a l'adresse IP 192.168.56.2.