Discard interfaces which hasn't device.(lo,virtual).

pym/utils/ip.py

@@ -179,6 +179,7 @@ def getRouteTable(onlyIface=[]):
             yield (network,dict(zip(routeParams[0::2],routeParams[1::2])))
 
 def getInterfaces():
-    """Get available interfaces"""
-    return filter(lambda x:x != "lo",
-           listDirectory('/sys/class/net'))
+    """Get available interfaces (discard which hasn't device)"""
+    sysNet = "/sys/class/net"
+    return filter(lambda x:path.exists(path.join(sysNet,x,"device")),
+           listDirectory(sysNet))