]> Depending on configuration backend chosen (see ), configuration mechanisms are different. The following sections describe details of specific configuration backends. Note that only one configuration backend can be used and its selection is determined during compilation time.

This legacy configuration backend allows Kea to use former BIND10 framework. That framework and this Kea configuration backend is no longer supported by ISC. It is currently developed as part of Bundy project (see Bundy homepage). See Bundy project documentation regarding configuration.

JSON is the default configuration backend and the only one supported as of 0.9 release. It assumes that the servers are started from command line (either directly or using a script, see TODO for details). JSON backend uses certain signals to influence certain behaviors. The configuration file is specified upon startup using -c parameter.

Configuration files for DHCPv4, DHCPv6 and DDNS modules are defined in extended JSON format. The basic JSON is defined in RFC 4627. Kea components use extended JSON, which extends basic format by allowing bash-style comments in the file. Comment lines must have hash (#) in the first column. Configuration file consists of a single object (often colloquially called a map) started with a curly bracket. It consists "Dhcp4", "Dhcp6", "DhcpDdns" and/or "Logging" objects. It is possible to define additional elements, but they will be ignored. That principle was chosen to ease configuration management. For example, it is possible to define Dhcp4, Dhcp6 and Logging elements in one configuration file that can be used to start both DHCPv4 and DHCPv6 components. When starting, DHCPv4 component will use Dhcp4 object to configure itself and Logging to configure logging parameters, while ignoring Dhcp6 object. For example, a very simple configuration for both DHCPv4 and DHCPv6 could look like this: # The whole configuration starts here. { # DHCPv4 specific configuration starts here. "Dhcp4": { "interfaces": [ "eth0" ], "valid-lifetime": 4000, "renew-timer": 1000, "rebind-timer": 2000, "subnet4": [{ "pool": "192.0.2.1-192.0.2.200", "subnet": "192.0.2.0/24" }], ... }, # DHCPv4 specific configuration ends here. # DHCPv6 specific configuration starts here. "Dhcp6": { "interfaces": [ "eth1" ], "preferred-lifetime": 3000, "valid-lifetime": 4000, "renew-timer": 1000, "rebind-timer": 2000, "subnet6": [{ "pool": "2001:db8::/80", "subnet": "2001:db8::/64" }], ... }, # DHCPv6 specific configuration ends here. # Logger parameters (that could be shared among several components) start here. # That section can be used by both DHCPv4 and DHCPv6 servers. "Logging": { "loggers": [{ "name": "*", "severity": "DEBUG" }], ... } # Logger parameters end here. # The whole configuration structure ends here. } More examples are available in the Kea source code in the doc/examples directory. To avoid repetition of mostly similar structures, specific examples will showcase only subset of parameters appropriate for a given context. For example, when discussing IPv6 subnets configuration in DHCPv6, only subnet6 parameters will be mentioned. It is implied that remaining elements (global that holds Dhcp6, Logging and possibly DhcpDdns) are present, but are omitted for clarity. Usually, locations where extra parameters may appear are denoted with ellipsis (triple dot).

It is sometimes convenient to refer to specific element in the configuration hierarchy. Each hierarchy level is separated by a slash. If there is an array, specific instance within that array is referred by a number in square brackets. For example, in the above configuration the valid-lifetime in Dhcp6 component can be referred to as Dhcp6/valid-lifetime, first interface for the DHCPv4 server as Dhcp4/interfaces[0] and the pool in the first IPv6 defined in DHCPv6 configuration as Dhcp6/subnet6[0]/pool.