config for disabling NAT port mapping

node/builder.go

@@ -195,7 +195,6 @@ var LibP2P = Options(
 	Override(new(routing.Routing), lp2p.Routing),
 
 	// Services
-	Override(NatPortMapKey, lp2p.NatPortMap),
 	Override(BandwidthReporterKey, lp2p.BandwidthCounter),
 	Override(AutoNATSvcKey, lp2p.AutoNATService),
 
@@ -277,6 +276,8 @@ func ConfigCommon(cfg *config.Common, enableLibp2pNode bool) Option {
 			Override(AddrsFactoryKey, lp2p.AddrsFactory(
 				cfg.Libp2p.AnnounceAddresses,
 				cfg.Libp2p.NoAnnounceAddresses)),
+
+			If(!cfg.Libp2p.DisableNatPortMap, Override(NatPortMapKey, lp2p.NatPortMap)),
 		),
 		Override(new(dtypes.MetadataDS), modules.Datastore(cfg.Backup.DisableMetadataLog)),
 	)

node/config/types.go

@@ -292,8 +292,21 @@ type Libp2p struct {
 	BootstrapPeers      []string
 	ProtectedPeers      []string
 
-	ConnMgrLow   uint
-	ConnMgrHigh  uint
+	// When not disabled (default), lotus asks NAT devices (e.g., routers), to
+	// open up an external port and forward it to the port lotus is running on.
+	// When this works (i.e., when your router supports NAT port forwarding),
+	// it makes the local lotus node accessible from the public internet
+	DisableNatPortMap bool
+
+	// ConnMgrLow is the number of connections that the basic connection manager
+	// will trim down to.
+	ConnMgrLow uint
+	// ConnMgrHigh is the number of connections that, when exceeded, will trigger
+	// a connection GC operation. Note: protected/recently formed connections don't
+	// count towards this limit.
+	ConnMgrHigh uint
+	// ConnMgrGrace is a time duration that new connections are immune from being
+	// closed by the connection manager.
 	ConnMgrGrace Duration
 }