doc: describe RA options for DNS configuration in ipv6.rst

Signed-off-by: Lars Seipel <ls@slrz.net>

diff --git a/doc/user/ipv6.rst b/doc/user/ipv6.rst
index 94095dd8bf9046d27b9b31cb8c50a4b97fddb19c..cc8fd18fee5f8ec46713105294b6a9301cb41087 100644 (file)
--- a/doc/user/ipv6.rst
+++ b/doc/user/ipv6.rst
@@ -181,6 +181,45 @@ Router Advertisement
 
    Default: don't advertise any MTU option.
 
+.. index::
+   single: ipv6 nd rdnss ipv6address [lifetime]
+   single: no ipv6 nd rdnss ipv6address [lifetime]
+.. clicmd:: [no] ipv6 nd rdnss ipv6address [lifetime]
+
+   Recursive DNS server address to advertise using the RDNSS (type 25) option
+   described in RFC8106. Can be specified more than once to advertise multiple
+   addresses. Note that hosts may choose to limit the number of RDNSS addresses
+   to track.
+
+   Optional parameter:
+
+   - ``lifetime``: the maximum time in seconds over which the specified address
+     may be used for domain name resolution. Value ``infinite`` represents
+     infinity (i.e. a value of all one bits (``0xffffffff``)). A value of 0
+     indicates that the address must no longer be used.
+     Range: ``(0-4294967295)``  Default: ``3 * ra-interval``
+
+   Default: do not emit RDNSS option
+
+.. index::
+   single: ipv6 nd dnssl domain-name-suffix [lifetime]
+   single: no ipv6 nd dnssl domain-name-suffix [lifetime]
+.. clicmd:: [no] ipv6 nd dnssl domain-name-suffix [lifetime]
+
+   Advertise DNS search list using the DNSSL (type 31) option described in
+   RFC8106. Specify more than once to advertise multiple domain name suffixes.
+   Host implementations may limit the number of honored search list entries.
+
+   Optional parameter:
+
+   - ``lifetime``: the maximum time in seconds over which the specified domain
+     suffix may be used in the course of  name resolution. Value ``infinite``
+     represents infinity (i.e. a value of all one bits (``0xffffffff``)). A
+     value of 0 indicates that the name suffix must no longer be used.
+     Range: ``(0-4294967295)``  Default: ``3 * ra-interval``
+
+   Default: do not emit DNSSL option
+
 Router Advertisement Configuration Example
 ==========================================
 A small example:
@@ -198,3 +237,4 @@ A small example:
    - :rfc:`4861` (Neighbor Discovery for IP Version 6 (IPv6))
    - :rfc:`6275` (Mobility Support in IPv6)
    - :rfc:`4191` (Default Router Preferences and More-Specific Routes)
+   - :rfc:`8106` (IPv6 Router Advertisement Options for DNS Configuration)