VRRP: addition of rfc3768-compatibility definition

Added the details of rfc3768-compatibility option and its command

docs/configexamples/ha.rst

@@ -6,8 +6,8 @@ This document walks you through a complete HA setup of two VyOS machines. This
 design is based on a VM as the primary router, and a physical machine as a
 backup, using VRRP, BGP, OSPF and conntrack sharing.
 
-The aim of this document is to walk you through setting everything up so you
+The aim of this document is to walk you through setting everything up, so 
-and up at a point where you can reboot any machine and not lose more than a few
+at a point where you can reboot any machine and not lose more than a few
 seconds worth of connectivity.
 
 Design

docs/configuration/highavailability/index.rst

@@ -152,6 +152,30 @@ instead.
   set high-availability vrrp group Foo peer-address 192.0.2.10
   set high-availability vrrp group Foo hello-source-address 192.0.2.15
 
+rfc3768-compatibility
+---------------------
+
+RFC 3768 defines a virtual MAC address to each VRRP virtual router.
+This virtual router MAC address will be used as the source in all periodic VRRP 
+messages sent by the active node. When the rfc3768-compatibilty option is set, 
+a new VRRP interface is created, to which the MAC address and the virtual IP 
+address is automatically assigned.
+
+.. code-block:: none
+
+   set high-availability vrrp group Foo rfc3768-compatibility
+
+Verification
+
+.. code-block:: none
+
+   $show interfaces ethernet eth0v10
+   eth0v10@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue 
+   state UP group default qlen 1000
+   link/ether 00:00:5e:00:01:0a brd ff:ff:ff:ff:ff:ff
+   inet 172.25.0.247/16 scope global eth0v10
+   valid_lft forever preferred_lft forever
+
 Scripting
 ---------