pppoe: add IPv6 DHCPv6-PD documentation

1 files changed, 50 insertions, 0 deletions

diff --git a/docs/interfaces/pppoe.rst b/docs/interfaces/pppoe.rst
index 8a7f027f..d9b5aa3d 100644
--- a/docs/interfaces/pppoe.rst
+++ b/docs/interfaces/pppoe.rst
@@ -167,6 +167,38 @@ IPv6
    Use this command to enable acquisition of IPv6 address using stateless
    autoconfig (SLAAC).
 
+Prefix Delegation (DHCPv6-PD)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+VyOS 1.3 (equuleus) supports DHCPv6-PD. DHCPv6 Prefix Delegation is supported
+by most ISPs who provide native IPv6 for consumers on fixed networks.
+
+.. cfgcmd:: set interfaces pppoe <interface> dhcpv6-option delegate <prefix-interface> interfaces-id <id>
+
+   This statement specifies the interface id.  ID must be a decimal integer.
+   It will be combined with the delegated prefix and the sla-id to form a
+   complete interface address. The default is to use the EUI-64 address of the
+   interface.
+
+   Example:
+
+   Using `<id>` value 65535 will assign IPv6 address <prefix>::ffff to the
+   interface.
+
+.. cfgcmd:: set interfaces pppoe <interface> dhcpv6-option delegate <prefix-interface> sla-id <id>
+
+   This statement specifies the identifier value of the site-level aggregator
+   (SLA) on the interface. ID must be a decimal number greater then 0 which
+   fits in the length of SLA IDs (see below). For example, if ID is 1 and the
+   client is delegated an IPv6 prefix 2001:db8:ffff::/48, dhcp6c will combine
+   the two values into a single IPv6 prefix, 2001:db8:ffff:1::/64, and will
+   configure the prefix on the specified interface.
+
+.. cfgcmd:: set interfaces pppoe <interface> dhcpv6-option delegate <prefix-interface> sla-len <len>
+
+   This statement specifies the length of the SLA ID in bits. `<len> must be a
+   decimal number between 0 and 128. If the length is not specified by this
+   statement, the default value 16 will be used.
 
 Operation
 =========
@@ -276,3 +308,21 @@ which is the default VLAN for Deutsche Telekom:
   set interfaces pppoe pppoe0 authentication password 'secret'
   set interfaces pppoe pppoe0 source-interface 'eth0.7'
 
+
+IPv6 DHCPv6-PD Example
+----------------------
+
+The following configuration will assign a /64 prefix out of a /56 delegation
+to eth0. The IPv6 address assigned to eth0 will be <prefix>::ffff/64.
+If you do not know the prefix size delegated to you, start with sla-len 0.
+
+.. code-block:: none
+
+  set interfaces pppoe pppoe0 authentication user vyos
+  set interfaces pppoe pppoe0 authentication password vyos
+  set interfaces pppoe pppoe0 dhcpv6-options delegate eth0 interface-id 65535
+  set interfaces pppoe pppoe0 dhcpv6-options delegate eth0 sla-id 0
+  set interfaces pppoe pppoe0 dhcpv6-options delegate eth0 sla-len 8
+  set interfaces pppoe pppoe0 ipv6 address autoconf
+  set interfaces pppoe pppoe0 ipv6 enable
+  set interfaces pppoe pppoe0 source-interface eth1