Doc: Document RAdv "custom option" configuration definition

diff --git a/doc/bird.sgml b/doc/bird.sgml
index 29e12b7a6fe78683de45a75a0dd9af4b3db37d39..52936f0edadf4289c052dfac3ce4cf5704bf6232 100644 (file)
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -4549,6 +4549,21 @@ definitions, prefix definitions and DNS definitions:
        options and there is a short variant <cf>dnssl <m/domain/</cf> that just
        specifies one DNS search domain.
 
+       <tag><label id="radv-custom-option">custom option type <m/number/ value <m/binary/</tag>
+       Custom option definitions allow to define an arbitrary option to
+       advertise. You need to specify the option type number and the binary
+       payload of the option. The length field is calculated automatically.
+       Like <cf/rdnss/ above, multiple definitions are cumulative, they can
+       be used also as interface-specific options.
+
+       The following example advertises PREF64 option (<rfc id="8781">) with
+       prefix <cf>2001:db8:a:b::/96</cf> and the lifetime of <cf/1 hour/:
+
+       <label id="radv-custom-option-exam">
+<p><code>
+custom option type 38 value hex:0e10:2001:0db8:000a:000b:0000:0000;
+</code>
+
        <tag><label id="radv-trigger">trigger <m/prefix/</tag>
        RAdv protocol could be configured to change its behavior based on
        availability of routes. When this option is used, the protocol waits in
@@ -4678,6 +4693,10 @@ definitions, prefix definitions and DNS definitions:
        <tag><label id="radv-iface-dnssl-local">dnssl local <m/switch/</tag>
        Use only local DNSSL definitions for this interface. See <cf/rdnss local/
        option above. Default: no.
+
+       <tag><label id="radv-iface-custom-local">custom option local <m/switch/</tag>
+       Use only local custom option definitions for this interface. See <cf/rdnss local/
+       option above. Default: no.
 </descrip>
 
 <p>Prefix specific options