Added Test case "Add IPv4 Address And Modify IPv4 Address"

Changes:

    - Added new test case

Tested:

    - Tested adding new IP and modifying IP and modifying it back.

Change-Id: I64fe51ec9b343c20c646e6a15c9ab3465549527f
Signed-off-by: Sweta Potthuri <spotthur@in.ibm.com>
diff --git a/redfish/managers/test_bmc_network_conf.robot b/redfish/managers/test_bmc_network_conf.robot
index d91b372..78768ba 100644
--- a/redfish/managers/test_bmc_network_conf.robot
+++ b/redfish/managers/test_bmc_network_conf.robot
@@ -493,6 +493,15 @@
 
      Update IP Address  ${test_ipv4_addr}  ${test_ipv4_addr2}  ${test_subnet_mask}  ${test_gateway}
 
+Verify Modifying IP Address Multiple Times
+    [Documentation]  Verify modifying IP address multiple times.
+    [Tags]  Verify_Modifying_IP_Address_Multiple_Times
+    [Teardown]  Run Keywords
+    ...  Delete IP Address  ${test_ipv4_addr}  AND  Test Teardown Execution
+
+    Add IP Address  ${test_ipv4_addr}  ${test_subnet_mask}  ${test_gateway}
+    Update IP Address  ${test_ipv4_addr}  ${test_ipv4_addr2}  ${test_subnet_mask}  ${test_gateway}
+    Update IP Address  ${test_ipv4_addr2}  ${test_ipv4_addr}  ${test_subnet_mask}  ${test_gateway}
 
 Configure Invalid Values For DNS Server
     [Documentation]  Configure invalid values for DNS server and expect an error.