disable use of mac by default.

plugins.cfg

@@ -14,7 +14,7 @@ enabled = False
 debug = True
 
 # If you know you won't be able to get the clients HW address then use this.
-only_ip = True
+use_mac = False
 
 # Command templates for arping and iptables.
 # Arping might block so make sure you use a timeout and limit the number of

plugins/iptables.py

@@ -71,7 +71,7 @@ def run(arg):
         pass
 
     # If HW address was found, use it now.
-    if client_mac:
+    if client_mac and config.getboolean('iptables', 'use_mac'):
         l.debug('Found client HW address: {hw}'.format(
             hw=client_mac
         ))