Added new test for VMI menu

Changes:
    - Added test
    "Disable VMI DHCPv6 Property And Check Persistency On BMC Reboot"

Tested:
    - Ran successfully  test_vmi.robot

Change-Id: I3b267f3aae0ecbc1626cae0de8c2a1b8e4caebe5
Signed-off-by: Megha G N <Megha.G.N@ibm.com>
diff --git a/openpower/ext_interfaces/test_vmi.robot b/openpower/ext_interfaces/test_vmi.robot
index 7203f01..a392670 100644
--- a/openpower/ext_interfaces/test_vmi.robot
+++ b/openpower/ext_interfaces/test_vmi.robot
@@ -8,7 +8,7 @@
 Test Teardown     FFDC On Test Case Fail
 Suite Teardown    Run Keyword And Ignore Error  Suite Teardown Execution
 
-Test Tags        Vmi
+Test Tags         Vmi
 
 *** Variables ***
 
@@ -602,6 +602,22 @@
     Verify VMI Network Interface Details  ${default}  DHCP  ${default}  ${default}
 
 
+Disable VMI DHCPv6 Property And Check Persistency On BMC Reboot
+    [Documentation]  Disable VMI DHCPv6 property and verify its persistency on
+    ...  BMC reboot.
+    [Tags]  Disable_VMI_DHCPv6_Property_And_Check_Persistency_On_BMC_Reboot
+    [Setup]  Set VMI DHCPv6 Property  Enabled
+
+    Set VMI DHCPv6 Property  Disabled
+
+    # Reboot BMC and verify persistency.
+    OBMC Reboot (off)
+
+    # Verify IPv6 address origin is set to Static and DHCPv6 address is erased.
+    ${vmi_ipv6addr}=  Verify VMI IPv6 Address  Static
+    Should Be Equal  ${vmi_ipv6addr["Address"]}  ${default_ipv6addr}
+
+
 *** Keywords ***
 
 Suite Setup Execution