@@ -100,6 +100,24 @@ func (e ambigousResultsError) Error() string {

 func (ambigousResultsError) InvalidParameter() {}

+type conflictError struct {

+	cause error

+}

+

+func (e conflictError) Error() string {

+	return e.cause.Error()

+}

+

+func (e conflictError) Cause() error {

+	return e.cause

+}

+

+func (e conflictError) Conflict() {}

+

+func nameConflict(name string) error {

+	return conflictError{libnetwork.NetworkNameError(name)}

+}

+

 func (n *networkRouter) getNetwork(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

 	if err := httputils.ParseForm(r); err != nil {

 		return err

@@ -225,7 +243,7 @@ func (n *networkRouter) postNetworkCreate(ctx context.Context, w http.ResponseWr

 	}

 	if nws, err := n.cluster.GetNetworksByName(create.Name); err == nil && len(nws) > 0 {

-		return libnetwork.NetworkNameError(create.Name)

+		return nameConflict(create.Name)

 	}

 	nw, err := n.backend.CreateNetwork(create)

@@ -235,7 +253,7 @@ func (n *networkRouter) postNetworkCreate(ctx context.Context, w http.ResponseWr

 			// check if user defined CheckDuplicate, if set true, return err

 			// otherwise prepare a warning message

 			if create.CheckDuplicate {

-				return libnetwork.NetworkNameError(create.Name)

+				return nameConflict(create.Name)

 			}

 			warning = libnetwork.NetworkNameError(create.Name).Error()

 		}

@@ -35,7 +35,7 @@ func (s *DockerSuite) TestAPINetworkCreateDelete(c *check.C) {

 			CheckDuplicate: true,

 		},

 	}

-	id := createNetwork(c, config, true)

+	id := createNetwork(c, config, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, name), checker.Equals, true)

 	// delete the network and make sure it is deleted

@@ -60,14 +60,14 @@ func (s *DockerSuite) TestAPINetworkCreateCheckDuplicate(c *check.C) {

 	}

 	// Creating a new network first

-	createNetwork(c, configOnCheck, true)

+	createNetwork(c, configOnCheck, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, name), checker.Equals, true)

 	// Creating another network with same name and CheckDuplicate must fail

-	createNetwork(c, configOnCheck, false)

+	createNetwork(c, configOnCheck, http.StatusConflict)

 	// Creating another network with same name and not CheckDuplicate must succeed

-	createNetwork(c, configNotCheck, true)

+	createNetwork(c, configNotCheck, http.StatusCreated)

 }

 func (s *DockerSuite) TestAPINetworkFilter(c *check.C) {

@@ -116,7 +116,7 @@ func (s *DockerSuite) TestAPINetworkInspectUserDefinedNetwork(c *check.C) {

 			Options: map[string]string{"foo": "bar", "opts": "dopts"},

 		},

 	}

-	id0 := createNetwork(c, config, true)

+	id0 := createNetwork(c, config, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, "br0"), checker.Equals, true)

 	nr := getNetworkResource(c, id0)

@@ -139,7 +139,7 @@ func (s *DockerSuite) TestAPINetworkConnectDisconnect(c *check.C) {

 	config := types.NetworkCreateRequest{

 		Name: name,

 	}

-	id := createNetwork(c, config, true)

+	id := createNetwork(c, config, http.StatusCreated)

 	nr := getNetworkResource(c, id)

 	c.Assert(nr.Name, checker.Equals, name)

 	c.Assert(nr.ID, checker.Equals, id)

@@ -187,7 +187,7 @@ func (s *DockerSuite) TestAPINetworkIPAMMultipleBridgeNetworks(c *check.C) {

 			IPAM:   ipam0,

 		},

 	}

-	id0 := createNetwork(c, config0, true)

+	id0 := createNetwork(c, config0, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, "test0"), checker.Equals, true)

 	ipam1 := &network.IPAM{

@@ -202,7 +202,7 @@ func (s *DockerSuite) TestAPINetworkIPAMMultipleBridgeNetworks(c *check.C) {

 			IPAM:   ipam1,

 		},

 	}

-	createNetwork(c, config1, false)

+	createNetwork(c, config1, http.StatusForbidden)

 	c.Assert(isNetworkAvailable(c, "test1"), checker.Equals, false)

 	ipam2 := &network.IPAM{

@@ -217,20 +217,20 @@ func (s *DockerSuite) TestAPINetworkIPAMMultipleBridgeNetworks(c *check.C) {

 			IPAM:   ipam2,

 		},

 	}

-	createNetwork(c, config2, true)

+	createNetwork(c, config2, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, "test2"), checker.Equals, true)

 	// remove test0 and retry to create test1

 	deleteNetwork(c, id0, true)

-	createNetwork(c, config1, true)

+	createNetwork(c, config1, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, "test1"), checker.Equals, true)

 	// for networks w/o ipam specified, docker will choose proper non-overlapping subnets

-	createNetwork(c, types.NetworkCreateRequest{Name: "test3"}, true)

+	createNetwork(c, types.NetworkCreateRequest{Name: "test3"}, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, "test3"), checker.Equals, true)

-	createNetwork(c, types.NetworkCreateRequest{Name: "test4"}, true)

+	createNetwork(c, types.NetworkCreateRequest{Name: "test4"}, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, "test4"), checker.Equals, true)

-	createNetwork(c, types.NetworkCreateRequest{Name: "test5"}, true)

+	createNetwork(c, types.NetworkCreateRequest{Name: "test5"}, http.StatusCreated)

 	c.Assert(isNetworkAvailable(c, "test5"), checker.Equals, true)

 	for i := 1; i < 6; i++ {

@@ -253,9 +253,8 @@ func createDeletePredefinedNetwork(c *check.C, name string) {

 			CheckDuplicate: true,

 		},

 	}

-	shouldSucceed := false

-	createNetwork(c, config, shouldSucceed)

-	deleteNetwork(c, name, shouldSucceed)

+	createNetwork(c, config, http.StatusForbidden)

+	deleteNetwork(c, name, false)

 }

 func isNetworkAvailable(c *check.C, name string) bool {

@@ -316,22 +315,22 @@ func getNetworkResource(c *check.C, id string) *types.NetworkResource {

 	return &nr

 }

-func createNetwork(c *check.C, config types.NetworkCreateRequest, shouldSucceed bool) string {

+func createNetwork(c *check.C, config types.NetworkCreateRequest, expectedStatusCode int) string {

 	resp, body, err := request.Post("/networks/create", request.JSONBody(config))

 	c.Assert(err, checker.IsNil)

 	defer resp.Body.Close()

-	if !shouldSucceed {

-		c.Assert(resp.StatusCode, checker.Not(checker.Equals), http.StatusCreated)

-		return ""

-	}

-	c.Assert(resp.StatusCode, checker.Equals, http.StatusCreated)

+	c.Assert(resp.StatusCode, checker.Equals, expectedStatusCode)

-	var nr types.NetworkCreateResponse

-	err = json.NewDecoder(body).Decode(&nr)

-	c.Assert(err, checker.IsNil)

+	if expectedStatusCode == http.StatusCreated {

+		var nr types.NetworkCreateResponse

+		err = json.NewDecoder(body).Decode(&nr)

+		c.Assert(err, checker.IsNil)

-	return nr.ID

+		return nr.ID

+	} else {

+		return ""

+	}

 }

 func connectNetwork(c *check.C, nid, cid string) {