client.go   |  6 +++++-
 logging.go  |  3 +++
 peer.go     |  7 ++++---
 peerconn.go | 33 +++++++++++++++++++++++----------

diff --git a/client.go b/client.go
index ed1a0c714c85fb382af45cde52ebdcf2d07d0b1d..f0587686502ce6bdfab0339874287626eca845ea 100644
--- a/client.go
+++ b/client.go
@@ -1016,6 +1016,10 @@ 		return nil, fmt.Errorf("during bt handshake: %w", err)
 	}
 	cl.lock()
 	t = cl.torrentsByShortHash[ih]
+	if t.infoHashV2.Ok && *t.infoHashV2.Value.ToShort() == ih {
+		torrent.Add("v2 handshakes received", 1)
+		c.v2 = true
+	}
 	cl.unlock()
 	return
 }
@@ -1662,7 +1666,7 @@ 		}
 	}
 	c.peerImpl = c
 	c.logger = cl.logger.WithDefaultLevel(log.Warning)
-	c.logger = c.logger.WithContextText(fmt.Sprintf("%T %p", c, c))
+	c.logger = c.logger.WithContextText(fmt.Sprintf("%T %p", c, c)).WithNames(protocolLoggingName)
 	c.setRW(connStatsReadWriter{nc, c})
 	c.r = &rateLimitedReader{
 		l: cl.config.DownloadRateLimiter,
diff --git a/logging.go b/logging.go
new file mode 100644
index 0000000000000000000000000000000000000000..bfc985c833085068883408ee250c0169b53c84b3
--- /dev/null
+++ b/logging.go
@@ -0,0 +1,3 @@
+package torrent
+
+const protocolLoggingName = "protocol"
diff --git a/peer.go b/peer.go
index 37d7ca57f02914ccf59059ecff8a0fe570a91b2d..71b8e855f9c6d5a27f569ab4b64a40a398f882cc 100644
--- a/peer.go
+++ b/peer.go
@@ -96,7 +96,8 @@ 		peerAllowedFast   typedRoaring.Bitmap[pieceIndex]
 
 		PeerMaxRequests maxRequests // Maximum pending requests the peer allows.
 
-		logger log.Logger
+		logger         log.Logger
+		protocolLogger log.Logger
 	}
 
 	PeerSource string
@@ -225,9 +226,9 @@ 	}
 	if cn.choking {
 		c('c')
 	}
-	c('-')
+	c(':')
 	ret += cn.connectionFlags()
-	c('-')
+	c(':')
 	if cn.peerInterested {
 		c('i')
 	}
diff --git a/peerconn.go b/peerconn.go
index 232da671be70202ece82f730dd6fa81c9e5ceb22..8bf510ead59dd072e2c891ac25157af9baa222b9 100644
--- a/peerconn.go
+++ b/peerconn.go
@@ -183,20 +183,30 @@ func (cn *PeerConn) peerPieces() *roaring.Bitmap {
 	return &cn._peerPieces
 }
 
-func (cn *PeerConn) connectionFlags() (ret string) {
-	c := func(b byte) {
-		ret += string([]byte{b})
+func (cn *PeerConn) connectionFlags() string {
+	var sb strings.Builder
+	add := func(s string) {
+		if sb.Len() > 0 {
+			sb.WriteByte(',')
+		}
+		sb.WriteString(s)
+	}
+	// From first relevant to last.
+	add(string(cn.Discovery))
+	if cn.utp() {
+		add("U")
 	}
 	if cn.cryptoMethod == mse.CryptoMethodRC4 {
-		c('E')
+		add("E")
 	} else if cn.headerEncrypted {
-		c('e')
+		add("e")
 	}
-	ret += string(cn.Discovery)
-	if cn.utp() {
-		c('U')
+	if cn.v2 {
+		add("v2")
+	} else {
+		add("v1")
 	}
-	return
+	return sb.String()
 }
 
 func (cn *PeerConn) utp() bool {
@@ -883,7 +893,7 @@ 			err = c.onReadExtendedMsg(msg.ExtendedID, msg.ExtendedPayload)
 		case pp.Hashes:
 			err = c.onReadHashes(&msg)
 		case pp.HashRequest, pp.HashReject:
-			c.logger.Levelf(log.Info, "received unimplemented BitTorrent v2 message: %v", msg.Type)
+			c.protocolLogger.Levelf(log.Info, "received unimplemented BitTorrent v2 message: %v", msg.Type)
 		default:
 			err = fmt.Errorf("received unknown message type: %#v", msg.Type)
 		}
@@ -1241,6 +1251,9 @@ 		return
 	}
 	info := pc.t.info
 	if !info.HasV2() {
+		return
+	}
+	if !pc.v2 {
 		return
 	}
 	baseLayer := pp.Integer(merkle.Log2RoundingUp(merkle.RoundUpToPowerOfTwo(