diff --git a/config.go b/config.go
index 40d885810b..fc04c9ff16 100644
--- a/config.go
+++ b/config.go
@@ -1,12 +1,14 @@
 package docker
 
 import (
-	"github.com/dotcloud/docker/engine"
 	"net"
+
+	"github.com/dotcloud/docker/engine"
+	"github.com/dotcloud/docker/networkdriver"
 )
 
 const (
-	DefaultNetworkMtu    = 1500
+	defaultNetworkMtu    = 1500
 	DisableNetworkBridge = "none"
 )
 
@@ -47,9 +49,16 @@ func DaemonConfigFromJob(job *engine.Job) *DaemonConfig {
 	if mtu := job.GetenvInt("Mtu"); mtu != 0 {
 		config.Mtu = mtu
 	} else {
-		config.Mtu = DefaultNetworkMtu
+		config.Mtu = GetDefaultNetworkMtu()
 	}
 	config.DisableNetwork = job.Getenv("BridgeIface") == DisableNetworkBridge
 
 	return config
 }
+
+func GetDefaultNetworkMtu() int {
+	if iface, err := networkdriver.GetDefaultRouteIface(); err == nil {
+		return iface.MTU
+	}
+	return defaultNetworkMtu
+}
diff --git a/docker/docker.go b/docker/docker.go
index aaeced95f6..d92f4d98ea 100644
--- a/docker/docker.go
+++ b/docker/docker.go
@@ -2,15 +2,16 @@ package main
 
 import (
 	"fmt"
+	"log"
+	"os"
+	"strings"
+
 	"github.com/dotcloud/docker"
 	"github.com/dotcloud/docker/api"
 	"github.com/dotcloud/docker/engine"
 	flag "github.com/dotcloud/docker/pkg/mflag"
 	"github.com/dotcloud/docker/sysinit"
 	"github.com/dotcloud/docker/utils"
-	"log"
-	"os"
-	"strings"
 )
 
 var (
@@ -42,7 +43,7 @@ func main() {
 		flInterContainerComm = flag.Bool([]string{"#icc", "-icc"}, true, "Enable inter-container communication")
 		flGraphDriver        = flag.String([]string{"s", "-storage-driver"}, "", "Force the docker runtime to use a specific storage driver")
 		flHosts              = docker.NewListOpts(docker.ValidateHost)
-		flMtu                = flag.Int([]string{"#mtu", "-mtu"}, docker.DefaultNetworkMtu, "Set the containers network mtu")
+		flMtu                = flag.Int([]string{"#mtu", "-mtu"}, 0, "Set the containers network MTU; if no value is provided: default to the default route MTU or 1500 if not default route is available")
 	)
 	flag.Var(&flDns, []string{"#dns", "-dns"}, "Force docker to use specific DNS servers")
 	flag.Var(&flHosts, []string{"H", "-host"}, "tcp://host:port, unix://path/to/socket, fd://* or fd://socketfd to use in daemon mode. Multiple sockets can be specified")
diff --git a/docs/sources/reference/commandline/cli.rst b/docs/sources/reference/commandline/cli.rst
index a4d3022867..ae77080309 100644
--- a/docs/sources/reference/commandline/cli.rst
+++ b/docs/sources/reference/commandline/cli.rst
@@ -80,6 +80,7 @@ Commands
       -r, --restart=true: Restart previously running containers
       -s, --storage-driver="": Force the docker runtime to use a specific storage driver
       -v, --version=false: Print version information and quit
+      -mtu, --mtu=0: Set the containers network MTU; if no value is provided: default to the default route MTU or 1500 if not default route is available
 
 The Docker daemon is the persistent process that manages containers.  Docker uses the same binary for both the 
 daemon and client.  To run the daemon you provide the ``-d`` flag.
diff --git a/integration/utils_test.go b/integration/utils_test.go
index 060a447131..450cb7527f 100644
--- a/integration/utils_test.go
+++ b/integration/utils_test.go
@@ -4,9 +4,6 @@ import (
 	"archive/tar"
 	"bytes"
 	"fmt"
-	"github.com/dotcloud/docker"
-	"github.com/dotcloud/docker/engine"
-	"github.com/dotcloud/docker/utils"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -16,6 +13,10 @@ import (
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/dotcloud/docker"
+	"github.com/dotcloud/docker/engine"
+	"github.com/dotcloud/docker/utils"
 )
 
 // This file contains utility functions for docker's unit test suite.
@@ -32,7 +33,7 @@ func mkRuntime(f utils.Fataler) *docker.Runtime {
 	config := &docker.DaemonConfig{
 		Root:        root,
 		AutoRestart: false,
-		Mtu:         docker.DefaultNetworkMtu,
+		Mtu:         docker.GetDefaultNetworkMtu(),
 	}
 
 	eng, err := engine.New(root)
diff --git a/networkdriver/utils.go b/networkdriver/utils.go
index 6f6dbe4f18..0a4ef70c95 100644
--- a/networkdriver/utils.go
+++ b/networkdriver/utils.go
@@ -2,13 +2,16 @@ package networkdriver
 
 import (
 	"encoding/binary"
+	"errors"
 	"fmt"
-	"github.com/dotcloud/docker/pkg/netlink"
 	"net"
+
+	"github.com/dotcloud/docker/pkg/netlink"
 )
 
 var (
 	networkGetRoutesFct = netlink.NetworkGetRoutes
+	ErrNoDefaultRoute   = errors.New("no default route")
 )
 
 func CheckNameserverOverlaps(nameservers []string, toCheck *net.IPNet) error {
@@ -100,3 +103,16 @@ func GetIfaceAddr(name string) (net.Addr, error) {
 	}
 	return addrs4[0], nil
 }
+
+func GetDefaultRouteIface() (*net.Interface, error) {
+	rs, err := networkGetRoutesFct()
+	if err != nil {
+		return nil, fmt.Errorf("unable to get routes: %v", err)
+	}
+	for _, r := range rs {
+		if r.Default {
+			return r.Iface, nil
+		}
+	}
+	return nil, ErrNoDefaultRoute
+}