help()
{
cat << EOF
-Usage: $prog [-n node_ip][-s slice] [-i key] -d dummynetbox_ip -p port [-U] [-t timeout[STRING]] ipfw_configuration_parameters \n
+Usage: $prog -p port [-U] [-t timeout[STRING]] ipfw_configuration_parameters \n
-h show help \n
-p specify the port to configure \n
-t specify the timeout. STRING can be "1minute" or "4hours" (default 1 hour) \n