diff --git a/README.md b/README.md
index e22096291463847c455a42991099926b8b07a934..d748d88c488917c2552f52e0f00fb214efa95c30 100644
--- a/README.md
+++ b/README.md
@@ -77,7 +77,8 @@ docker exec -ti rweb /bin/bash
 |30997|FRPC console|
 |30500-30899|FRP server dynamic ports|
 |9399|Virtualbox web interface|
-|9000-9389|Virtualbox dynamic ports|
+|9000-9389|Virtualbox dynamic ports (RDP)|
+|31000-31499|Virtualbox dynamic ports (Other use)|
 
 ## tw1 migration (gcp)