1 files changed, 40 insertions, 2 deletions
diff --git a/docs/high-availability.rst b/docs/high-availability.rst
index 9f4dd35d..07818e92 100644
--- a/docs/high-availability.rst
+++ b/docs/high-availability.rst
@@ -61,12 +61,50 @@ VRRP priority can be set with ``priority`` option:
 
   set high-availability vrrp group Foo priority 200
 
-The priority must be an interger number from 1 to 255. Higher priority value increases router's precedence in the master elections.
+The priority must be an integer number from 1 to 255. Higher priority value increases router's precedence in the master elections.
+
+Sync groups
+-----------
+
+A sync group allows VRRP groups to transition together.  
+
+.. code-block:: sh
+
+    edit high-availability
+    set sync-group MAIN member VLAN9
+    set sync-group MAIN member VLAN20
+
+In the following example, when VLAN9 transitions, VLAN20 will also transition:
+
+.. code-block:: sh
+
+    vrrp {
+        group VLAN9 {
+            interface eth0.9
+            virtual-address 10.9.1.1/24
+            priority 200
+            vrid 9
+        }
+        group VLAN20 {
+            interface eth0.20
+            priority 200
+            virtual-address 10.20.20.1/24
+            vrid 20
+        }
+        sync-group MAIN {
+            member VLAN20
+            member VLAN9
+        }
+    }
+
+
+.. warning:: All items in a sync group should be similarly configured.  If one VRRP group is set to a different premption delay or priority, it would result in an endless transition loop.
+
 
 Preemption
 ----------
 
-VRRP can use two modes: preemptive and non-preemptive. In the preemptive mode, if a router with a higher priority fails and then comes back, routers with lower priority will give up their master status. In non-preemptive mode, the newly elected master will keep the master status and the virtual address indenfinitely.
+VRRP can use two modes: preemptive and non-preemptive. In the preemptive mode, if a router with a higher priority fails and then comes back, routers with lower priority will give up their master status. In non-preemptive mode, the newly elected master will keep the master status and the virtual address indefinitely.
 
 By default VRRP uses preemption. You can disable it with the "no-preempt" option: