Note that --listeners>1 only works for Linux 3.9+.

README.md

@@ -51,15 +51,13 @@ Usage of ./go-mmproxy:
   -l string
     	Adress the proxy listens on (default "0.0.0.0:8443")
   -listeners int
-    	Number of listener sockets that will be opened for the listen address (default 1)
+    	Number of listener sockets that will be opened for the listen address (Linux 3.9+) (default 1)
   -mark int
     	The mark that will be set on outbound packets
   -v int
     	0 - no logging of individual connections
     	1 - log errors occuring in individual connections
     	2 - log all state changes of individual connections
-
-
 ```
 
 Example invocation:

main.go

@@ -42,7 +42,8 @@ func init() {
 	flag.IntVar(&verbose, "v", 0, `0 - no logging of individual connections
 1 - log errors occuring in individual connections
 2 - log all state changes of individual connections`)
-	flag.IntVar(&listeners, "listeners", 1, "Number of listener sockets that will be opened for the listen address")
+	flag.IntVar(&listeners, "listeners", 1,
+		"Number of listener sockets that will be opened for the listen address (Linux 3.9+)")
 }
 
 func readRemoteAddrPROXYv2(conn net.Conn, ctrlBuf []byte) (net.Addr, net.Addr, []byte, error) {