router: router.id is optional

connector/router/connector.go

@@ -90,9 +90,11 @@ func (c *routerConnector) Connect(ctx context.Context, conn net.Conn, network, a
 	af.ParseFrom(address)
 	req.Features = append(req.Features, af) // dst address
 
-	req.Features = append(req.Features, &relay.TunnelFeature{
-		ID: c.md.routerID,
-	})
+	if !c.md.routerID.IsZero() {
+		req.Features = append(req.Features, &relay.TunnelFeature{
+			ID: c.md.routerID,
+		})
+	}
 
 	if _, err := req.WriteTo(conn); err != nil {
 		return nil, err

connector/router/metadata.go

@@ -30,13 +30,5 @@ func (c *routerConnector) parseMetadata(md mdata.Metadata) (err error) {
 		c.md.routerID = relay.NewTunnelID(uuid[:])
 	}
 
-	if c.md.routerID.IsZero() {
-		uuid, err := uuid.NewUUID()
-		if err != nil {
-			return err
-		}
-		c.md.routerID = relay.NewTunnelID(uuid[:])
-	}
-
 	return
 }