diff --git a/weed/command/mount_std.go b/weed/command/mount_std.go
index a6d562d40..6eb836311 100644
--- a/weed/command/mount_std.go
+++ b/weed/command/mount_std.go
@@ -53,7 +53,7 @@ func RunMount(option *MountOptions, umask os.FileMode) bool {
 
 	filer := *option.filer
 	// parse filer grpc address
-	filerGrpcAddress, err := pb.ParseFilerGrpcAddress(filer)
+	filerGrpcAddress, err := pb.ParseServerToGrpcAddress(filer)
 	if err != nil {
 		glog.V(0).Infof("ParseFilerGrpcAddress: %v", err)
 		return true
diff --git a/weed/command/msg_broker.go b/weed/command/msg_broker.go
index b4b5855ff..db0b4148d 100644
--- a/weed/command/msg_broker.go
+++ b/weed/command/msg_broker.go
@@ -63,7 +63,7 @@ func (msgBrokerOpt *MessageBrokerOptions) startQueueServer() bool {
 
 	grace.SetupProfiling(*messageBrokerStandaloneOptions.cpuprofile, *messageBrokerStandaloneOptions.memprofile)
 
-	filerGrpcAddress, err := pb.ParseFilerGrpcAddress(*msgBrokerOpt.filer)
+	filerGrpcAddress, err := pb.ParseServerToGrpcAddress(*msgBrokerOpt.filer)
 	if err != nil {
 		glog.Fatal(err)
 		return false
diff --git a/weed/command/s3.go b/weed/command/s3.go
index d8e3e306b..c8292a7d5 100644
--- a/weed/command/s3.go
+++ b/weed/command/s3.go
@@ -137,7 +137,7 @@ func runS3(cmd *Command, args []string) bool {
 
 func (s3opt *S3Options) startS3Server() bool {
 
-	filerGrpcAddress, err := pb.ParseFilerGrpcAddress(*s3opt.filer)
+	filerGrpcAddress, err := pb.ParseServerToGrpcAddress(*s3opt.filer)
 	if err != nil {
 		glog.Fatal(err)
 		return false
diff --git a/weed/command/webdav.go b/weed/command/webdav.go
index 2bd4a3c61..781ea1e36 100644
--- a/weed/command/webdav.go
+++ b/weed/command/webdav.go
@@ -78,7 +78,7 @@ func (wo *WebDavOption) startWebDav() bool {
 	}
 
 	// parse filer grpc address
-	filerGrpcAddress, err := pb.ParseFilerGrpcAddress(*wo.filer)
+	filerGrpcAddress, err := pb.ParseServerToGrpcAddress(*wo.filer)
 	if err != nil {
 		glog.Fatal(err)
 		return false
diff --git a/weed/pb/grpc_client_server.go b/weed/pb/grpc_client_server.go
index 910114313..341718ae4 100644
--- a/weed/pb/grpc_client_server.go
+++ b/weed/pb/grpc_client_server.go
@@ -3,6 +3,7 @@ package pb
 import (
 	"context"
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	"net/http"
 	"strconv"
 	"strings"
@@ -108,51 +109,51 @@ func WithCachedGrpcClient(fn func(*grpc.ClientConn) error, address string, opts
 }
 
 func ParseServerToGrpcAddress(server string) (serverGrpcAddress string, err error) {
-	colonIndex := strings.LastIndex(server, ":")
-	if colonIndex < 0 {
-		return "", fmt.Errorf("server should have hostname:port format: %v", server)
-	}
 
-	port, parseErr := strconv.ParseUint(server[colonIndex+1:], 10, 64)
+	host, port, parseErr := hostAndPort(server)
 	if parseErr != nil {
 		return "", fmt.Errorf("server port parse error: %v", parseErr)
 	}
 
 	grpcPort := int(port) + 10000
 
-	return fmt.Sprintf("%s:%d", server[:colonIndex], grpcPort), nil
+	return fmt.Sprintf("%s:%d", host, grpcPort), nil
+}
+
+func hostAndPort(address string) (host string, port uint64, err error) {
+	colonIndex := strings.LastIndex(address, ":")
+	if colonIndex < 0 {
+		return "", 0, fmt.Errorf("server should have hostname:port format: %v", address)
+	}
+	port, err = strconv.ParseUint(address[colonIndex+1:], 10, 64)
+	if err != nil {
+		return "", 0,  fmt.Errorf("server port parse error: %v", err)
+	}
+
+	return address[:colonIndex], port, err
 }
 
 func ServerToGrpcAddress(server string) (serverGrpcAddress string) {
-	hostnameAndPort := strings.Split(server, ":")
-	if len(hostnameAndPort) != 2 {
-		return fmt.Sprintf("unexpected server address: %s", server)
-	}
 
-	port, parseErr := strconv.ParseUint(hostnameAndPort[1], 10, 64)
+	host, port, parseErr := hostAndPort(server)
 	if parseErr != nil {
-		return fmt.Sprintf("failed to parse port for %s:%s", hostnameAndPort[0], hostnameAndPort[1])
+		glog.Fatalf("server address %s parse error: %v", server, parseErr)
 	}
 
 	grpcPort := int(port) + 10000
 
-	return fmt.Sprintf("%s:%d", hostnameAndPort[0], grpcPort)
+	return fmt.Sprintf("%s:%d", host, grpcPort)
 }
 
 func GrpcAddressToServerAddress(grpcAddress string) (serverAddress string) {
-	hostnameAndPort := strings.Split(grpcAddress, ":")
-	if len(hostnameAndPort) != 2 {
-		return fmt.Sprintf("unexpected grpcAddress: %s", grpcAddress)
-	}
-
-	grpcPort, parseErr := strconv.ParseUint(hostnameAndPort[1], 10, 64)
+	host, grpcPort, parseErr := hostAndPort(grpcAddress)
 	if parseErr != nil {
-		return fmt.Sprintf("failed to parse port for %s:%s", hostnameAndPort[0], hostnameAndPort[1])
+		glog.Fatalf("server grpc address %s parse error: %v", grpcAddress, parseErr)
 	}
 
 	port := int(grpcPort) - 10000
 
-	return fmt.Sprintf("%s:%d", hostnameAndPort[0], port)
+	return fmt.Sprintf("%s:%d", host, port)
 }
 
 func WithMasterClient(master string, grpcDialOption grpc.DialOption, fn func(client master_pb.SeaweedClient) error) error {
@@ -197,19 +198,3 @@ func WithGrpcFilerClient(filerGrpcAddress string, grpcDialOption grpc.DialOption
 	}, filerGrpcAddress, grpcDialOption)
 
 }
-
-func ParseFilerGrpcAddress(filer string) (filerGrpcAddress string, err error) {
-	hostnameAndPort := strings.Split(filer, ":")
-	if len(hostnameAndPort) != 2 {
-		return "", fmt.Errorf("filer should have hostname:port format: %v", hostnameAndPort)
-	}
-
-	filerPort, parseErr := strconv.ParseUint(hostnameAndPort[1], 10, 64)
-	if parseErr != nil {
-		return "", fmt.Errorf("filer port parse error: %v", parseErr)
-	}
-
-	filerGrpcPort := int(filerPort) + 10000
-
-	return fmt.Sprintf("%s:%d", hostnameAndPort[0], filerGrpcPort), nil
-}
diff --git a/weed/server/filer_server.go b/weed/server/filer_server.go
index 22474a5e2..9e0770afa 100644
--- a/weed/server/filer_server.go
+++ b/weed/server/filer_server.go
@@ -153,7 +153,7 @@ func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption)
 func (fs *FilerServer) checkWithMaster() {
 
 	for _, master := range fs.option.Masters {
-		_, err := pb.ParseFilerGrpcAddress(master)
+		_, err := pb.ParseServerToGrpcAddress(master)
 		if err != nil {
 			glog.Fatalf("invalid master address %s: %v", master, err)
 		}
diff --git a/weed/util/fasthttp_util.go b/weed/util/fasthttp_util.go
index 82575af98..6c31a40da 100644
--- a/weed/util/fasthttp_util.go
+++ b/weed/util/fasthttp_util.go
@@ -18,6 +18,7 @@ var (
 		WriteTimeout:                  time.Second,
 		MaxIdleConnDuration:           time.Minute,
 		DisableHeaderNamesNormalizing: true, // If you set the case on your headers correctly you can enable this.
+		DialDualStack:                 true,
 	}
 
 	// Put everything in pools to prevent garbage.