diff --git a/lib/utilities.py b/lib/utilities.py
index 980d06b..f316b3b 100755
--- a/lib/utilities.py
+++ b/lib/utilities.py
@@ -3,7 +3,23 @@
 from robot.libraries.BuiltIn import BuiltIn
 import imp
 import string
+import random
 
+def random_mac():
+    r"""
+    Return random mac address in the following format.
+    Example: 00:01:6C:80:02:78
+    """
+    return ":".join(map(lambda x: "%02x" % x, (random.randint(0x00, 0xff)
+        for _ in range(6))))
+
+def random_ip():
+    r"""
+    Return random ip address in the following format.
+    Example: 9.3.128.100
+    """
+    return ".".join(map(str, (random.randint(0, 255)
+        for _ in range(4))))
 
 def get_sensor(module_name, value):
     m = imp.load_source('module.name', module_name)