<section id="stateless-dhcp6">
<title>Stateless DHCPv6 (Information-Request Message)</title>
- <para>Typically DHCPv6 is used to assign addresses and options. Those
- assignments (leases) have state that changes state over time, hence
- their name stateful. DHCPv6 also supports stateless mode,
- where clients simply request configuration options. This mode is
- considered lightweight from the server perspective, as it does require
- any state tracking. Hence its name.</para>
- <para>Kea server supports this mode out of the box. Clients may send
- Information-Request messages and the server will simply send back answers
- with requested options, if they are available in the server configuration.
- The server will attempt to use per subnet options first. If that fails for
- whatever reason, it will then try to provide options defined in the global
- scope.</para>
- <para>Stateless and stateful mode can be used together. No special configuration
- directives are required to handle this. Simply use the configuration for
- stateful clients and the stateless clients will get just options they requested.
- </para>
- <para>This usage of global options brings in an interesting observation.
- It is possible to run the server that provides just options and no addresses
- or prefixes. If the options have the same value in each subnet, the configuration
- may simply define required options in the global scope and skip subnet
- definitions altogether. Here's an example of such very simple configuration:
+ <para>Typically DHCPv6 is used to assign both addresses and options. These
+ assignments (leases) have state that changes over time, hence
+ their name, stateful. DHCPv6 also supports a stateless mode,
+ where clients request configuration options only. This mode is
+ considered lightweight from the server perspective, as it does not require
+ any state tracking; hence its name.</para>
+ <para>The Kea server supports stateless mode. Clients can send
+ Information-Request messages and the server will send back
+ answers with the requested options (providing the options are
+ available in the server configuration). The server will attempt to
+ use per-subnet options first. If that fails - for whatever reason - it
+ will then try to provide options defined in the global scope.</para>
+
+ <para>Stateless and stateful mode can be used together. No special
+ configuration directives are required to handle this. Simply use the
+ configuration for stateful clients and the stateless clients will get
+ just options they requested.</para>
+
+ <para>This usage of global options allows for an interesting case.
+ It is possible to run a server that provides just options and no
+ addresses or prefixes. If the options have the same value in each
+ subnet, the configuration can define required options in the global
+ scope and skip subnet definitions altogether. Here's a simple example of
+ such a configuration:
<screen>
"Dhcp6": {
"interfaces": [ "ethX" ],
"lease-database": { "type": "memfile" }
}
</screen>
- This very simple configuration will provide DNS servers information to all
- clients in the network, regardless of their location. Note that as of 0.9.1,
- Kea requires lease-database to be specified, even if it is not used.
- </para>
+ This very simple configuration will provide DNS server information
+ to all clients in the network, regardless of their location. Note the
+ specification of the memfile lease database: this is required since,
+ as of version 0.9.1, Kea requires a lease database to be specified
+ even if it is not used.</para>
</section>
<section id="dhcp6-relay-override">