diff --git a/net/ethtool.go b/net/ethtool.go
index 34209f0d..053a30ec 100644
--- a/net/ethtool.go
+++ b/net/ethtool.go
@@ -6,6 +6,7 @@ import "unsafe"
 
 const (
 	SIOCETHTOOL     = 0x8946     // linux/sockios.h
+	ETHTOOL_GTXCSUM = 0x00000016 // linux/ethtool.h
 	ETHTOOL_STXCSUM = 0x00000017 // linux/ethtool.h
 	IFNAMSIZ        = 16         // linux/if.h
 )
@@ -22,31 +23,38 @@ type EthtoolValue struct {
 	Data uint32
 }
 
+func ioctlEthtool(fd int, argp uintptr) error {
+	_, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL, uintptr(fd), uintptr(SIOCETHTOOL), argp)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
 // Disable TX checksum offload on specified interface
 func EthtoolTXOff(name string) error {
 	if len(name)+1 > IFNAMSIZ {
 		return fmt.Errorf("name too long")
 	}
 
-	value := EthtoolValue{ETHTOOL_STXCSUM, 0}
-	request := IFReqData{Data: uintptr(unsafe.Pointer(&value))}
-
-	copy(request.Name[:], name)
-
 	socket, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, 0)
 	if err != nil {
 		return err
 	}
 	defer syscall.Close(socket)
 
-	_, _, errno := syscall.RawSyscall(syscall.SYS_IOCTL,
-		uintptr(socket),
-		uintptr(SIOCETHTOOL),
-		uintptr(unsafe.Pointer(&request)))
+	// Request current value
+	value := EthtoolValue{Cmd: ETHTOOL_GTXCSUM}
+	request := IFReqData{Data: uintptr(unsafe.Pointer(&value))}
+	copy(request.Name[:], name)
 
-	if errno != 0 {
-		return errno
+	if err := ioctlEthtool(socket, uintptr(unsafe.Pointer(&request))); err != nil {
+		return err
+	}
+	if value.Data == 0 { // if already off, don't try to change
+		return nil
 	}
 
-	return nil
+	value = EthtoolValue{ETHTOOL_STXCSUM, 0}
+	return ioctlEthtool(socket, uintptr(unsafe.Pointer(&request)))
 }
diff --git a/prog/weaveutil/plugin_network.go b/prog/weaveutil/plugin_network.go
index 9ff52314..33c3a79a 100644
--- a/prog/weaveutil/plugin_network.go
+++ b/prog/weaveutil/plugin_network.go
@@ -10,11 +10,12 @@ import (
 )
 
 func createPluginNetwork(args []string) error {
-	if len(args) != 2 {
-		cmdUsage("create-plugin-network", "<network-name> <driver-name>")
+	if len(args) != 3 {
+		cmdUsage("create-plugin-network", "<network-name> <driver-name> <default-subnet>")
 	}
 	networkName := args[0]
 	driverName := args[1]
+	subnet := args[2]
 	d, err := newDockerClient()
 	if err != nil {
 		return err
@@ -24,8 +25,11 @@ func createPluginNetwork(args []string) error {
 			Name:           networkName,
 			CheckDuplicate: true,
 			Driver:         driverName,
-			IPAM:           docker.IPAMOptions{Driver: driverName},
-			Options:        map[string]interface{}{plugin.MulticastOption: "true"},
+			IPAM: docker.IPAMOptions{
+				Driver: driverName,
+				Config: []docker.IPAMConfig{{Subnet: subnet}},
+			},
+			Options: map[string]interface{}{plugin.MulticastOption: "true"},
 		})
 	if err != docker.ErrNetworkAlreadyExists && err != nil {
 		// Despite appearances to the contrary, CreateNetwork does
diff --git a/weave b/weave
index 7f5ef95d..bd748cba 100755
--- a/weave
+++ b/weave
@@ -1773,7 +1773,8 @@ launch_plugin_if_not_running() {
         return 1
     fi
     wait_for_status $PLUGIN_CONTAINER_NAME http_call_unix $PLUGIN_CONTAINER_NAME status.sock
-    util_op create-plugin-network weave weavemesh
+    WEAVE_IPAM_SUBNET=$(call_weave GET /ipinfo/defaultsubnet)
+    util_op create-plugin-network weave weavemesh $WEAVE_IPAM_SUBNET
 }
 
 plugin_disabled() {