diff --git a/p2p/net/conn/dial.go b/p2p/net/conn/dial.go
index 12f41688..b2d4908a 100644
--- a/p2p/net/conn/dial.go
+++ b/p2p/net/conn/dial.go
@@ -10,6 +10,7 @@ import (
 	addrutil "github.com/ipfs/go-libp2p/p2p/net/swarm/addr"
 	transport "github.com/ipfs/go-libp2p/p2p/net/transport"
 	peer "github.com/ipfs/go-libp2p/p2p/peer"
+	msmux "gx/ipfs/QmUeEcYJrzAEKdQXjzTxCgNZgc9sRuwharsvzzm5Gd2oGB/go-multistream"
 	manet "gx/ipfs/QmYVqhVfbK4BKvbW88Lhm26b3ud14sTBvcm1H7uWUx1Fkp/go-multiaddr-net"
 	context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
 	ma "gx/ipfs/QmcobAGsCjYt5DXoq9et9L8yR8er7o7Cu3DTvpaq12jYSz/go-multiaddr"
@@ -62,6 +63,17 @@ func (d *Dialer) Dial(ctx context.Context, raddr ma.Multiaddr, remote peer.ID) (
 			maconn = d.Wrapper(maconn)
 		}
 
+		cryptoProtoChoice := SecioTag
+		if !EncryptConnections {
+			cryptoProtoChoice = NoEncryptionTag
+		}
+
+		err = msmux.SelectProtoOrFail(cryptoProtoChoice, maconn)
+		if err != nil {
+			errOut = err
+			return
+		}
+
 		c, err := newSingleConn(ctx, d.LocalPeer, remote, maconn)
 		if err != nil {
 			maconn.Close()
diff --git a/p2p/net/conn/dial_test.go b/p2p/net/conn/dial_test.go
index 9f4923e2..c91fd5bf 100644
--- a/p2p/net/conn/dial_test.go
+++ b/p2p/net/conn/dial_test.go
@@ -13,6 +13,7 @@ import (
 	peer "github.com/ipfs/go-libp2p/p2p/peer"
 	tu "github.com/ipfs/go-libp2p/testutil"
 
+	msmux "gx/ipfs/QmUeEcYJrzAEKdQXjzTxCgNZgc9sRuwharsvzzm5Gd2oGB/go-multistream"
 	context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
 	ma "gx/ipfs/QmcobAGsCjYt5DXoq9et9L8yR8er7o7Cu3DTvpaq12jYSz/go-multiaddr"
 )
@@ -319,3 +320,32 @@ func TestDialerCloseEarlySecure(t *testing.T) {
 	// t.Skip("Skipping in favor of another test")
 	testDialerCloseEarly(t, true)
 }
+
+func TestMultistreamHeader(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	p1 := tu.RandPeerNetParamsOrFatal(t)
+
+	l1, err := Listen(ctx, p1.Addr, p1.ID, p1.PrivKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	p1.Addr = l1.Multiaddr() // Addr has been determined by kernel.
+
+	go func() {
+		_, _ = l1.Accept()
+	}()
+
+	con, err := net.Dial("tcp", l1.Addr().String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer con.Close()
+
+	err = msmux.SelectProtoOrFail(SecioTag, con)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/p2p/net/conn/listen.go b/p2p/net/conn/listen.go
index 84ff12e6..33b09756 100644
--- a/p2p/net/conn/listen.go
+++ b/p2p/net/conn/listen.go
@@ -11,11 +11,15 @@ import (
 	peer "github.com/ipfs/go-libp2p/p2p/peer"
 	"gx/ipfs/QmQopLATEYMNg7dVqZRNDfeE2S1yKy8zrRh5xnYiuqeZBn/goprocess"
 	goprocessctx "gx/ipfs/QmQopLATEYMNg7dVqZRNDfeE2S1yKy8zrRh5xnYiuqeZBn/goprocess/context"
+	msmux "gx/ipfs/QmUeEcYJrzAEKdQXjzTxCgNZgc9sRuwharsvzzm5Gd2oGB/go-multistream"
 	tec "gx/ipfs/QmWHgLqrghM9zw77nF6gdvT9ExQ2RB9pLxkd8sDHZf1rWb/go-temp-err-catcher"
 	context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
 	ma "gx/ipfs/QmcobAGsCjYt5DXoq9et9L8yR8er7o7Cu3DTvpaq12jYSz/go-multiaddr"
 )
 
+const SecioTag = "/secio/1.0.0"
+const NoEncryptionTag = "/plaintext/1.0.0"
+
 // ConnWrapper is any function that wraps a raw multiaddr connection
 type ConnWrapper func(transport.Conn) transport.Conn
 
@@ -31,6 +35,8 @@ type listener struct {
 	wrapper ConnWrapper
 
 	proc goprocess.Process
+
+	mux *msmux.MultistreamMuxer
 }
 
 func (l *listener) teardown() error {
@@ -98,6 +104,11 @@ func (l *listener) Accept() (net.Conn, error) {
 			maconn = l.wrapper(maconn)
 		}
 
+		_, _, err = l.mux.Negotiate(maconn)
+		if err != nil {
+			return nil, err
+		}
+
 		c, err := newSingleConn(ctx, l.local, "", maconn)
 		if err != nil {
 			if catcher.IsTemporary(err) {
@@ -150,9 +161,16 @@ func WrapTransportListener(ctx context.Context, ml transport.Listener, local pee
 		Listener: ml,
 		local:    local,
 		privk:    sk,
+		mux:      msmux.NewMultistreamMuxer(),
 	}
 	l.proc = goprocessctx.WithContextAndTeardown(ctx, l.teardown)
 
+	if EncryptConnections {
+		l.mux.AddHandler(SecioTag, nil)
+	} else {
+		l.mux.AddHandler(NoEncryptionTag, nil)
+	}
+
 	log.Debugf("Conn Listener on %s", l.Multiaddr())
 	log.Event(ctx, "swarmListen", l)
 	return l, nil
diff --git a/p2p/net/swarm/swarm.go b/p2p/net/swarm/swarm.go
index 543c01c2..b8e041e8 100644
--- a/p2p/net/swarm/swarm.go
+++ b/p2p/net/swarm/swarm.go
@@ -46,8 +46,8 @@ func init() {
 		LogOutput:              ioutil.Discard,
 	}
 
-	msstpt.AddTransport("/yamux", ymxtpt)
-	msstpt.AddTransport("/spdystream", spdy.Transport)
+	msstpt.AddTransport("/yamux/1.0.0", ymxtpt)
+	msstpt.AddTransport("/spdy/3.1.0", spdy.Transport)
 
 	PSTransport = msstpt
 }
diff --git a/p2p/protocol/identify/id.go b/p2p/protocol/identify/id.go
index 2f2dbef2..76212e57 100644
--- a/p2p/protocol/identify/id.go
+++ b/p2p/protocol/identify/id.go
@@ -22,7 +22,7 @@ import (
 var log = logging.Logger("net/identify")
 
 // ID is the protocol.ID of the Identify Service.
-const ID = "/ipfs/identify"
+const ID = "/ipfs/id/1.0.0"
 
 // LibP2PVersion holds the current protocol version for a client running this code
 // TODO(jbenet): fix the versioning mess.
diff --git a/p2p/protocol/ping/ping.go b/p2p/protocol/ping/ping.go
index 4b2200fb..7cb18b0e 100644
--- a/p2p/protocol/ping/ping.go
+++ b/p2p/protocol/ping/ping.go
@@ -18,7 +18,7 @@ var log = logging.Logger("ping")
 
 const PingSize = 32
 
-const ID = "/ipfs/ping"
+const ID = "/ipfs/ping/1.0.0"
 
 type PingService struct {
 	Host host.Host
diff --git a/p2p/protocol/relay/relay.go b/p2p/protocol/relay/relay.go
index 7c2f7c75..f46e4a5d 100644
--- a/p2p/protocol/relay/relay.go
+++ b/p2p/protocol/relay/relay.go
@@ -17,7 +17,7 @@ import (
 var log = logging.Logger("github.com/ipfs/go-libp2p/p2p/protocol/relay")
 
 // ID is the protocol.ID of the Relay Service.
-const ID protocol.ID = "/ipfs/relay"
+const ID protocol.ID = "/ipfs/relay/line/0.1.0"
 
 // Relay is a structure that implements ProtocolRelay.
 // It is a simple relay service which forwards traffic