Add explanatory comment about default port (PegaSysEng#1392)

notlesh · May 4, 2019 · 7cdb378 · 7cdb378
1 parent f9f83c6
commit 7cdb378
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/ethereum/p2p/src/main/java/tech/pegasys/pantheon/ethereum/p2p/network/netty/DeFramer.java b/ethereum/p2p/src/main/java/tech/pegasys/pantheon/ethereum/p2p/network/netty/DeFramer.java
@@ -171,7 +171,10 @@ private Peer createPeer(final PeerInfo peerInfo, final ChannelHandlerContext ctx
     final InetSocketAddress remoteAddress = ((InetSocketAddress) ctx.channel().remoteAddress());
     int port = peerInfo.getPort();
     if (port == 0) {
-      // Most peers advertise a port of "0", just set a default best guess in this case
+      // Most peers advertise a port of "0", just set a default best guess in this case.
+      // We can't simply use the remote address port because peers initiating inbound connections
+      // are free to choose any port they want for their side of the connection.  The remote port
+      // does not actually correspond to the peer's listening port.
       port = EnodeURL.DEFAULT_LISTENING_PORT;
     }
     return DefaultPeer.fromEnodeURL(