diff --git a/src/mqtt.js b/src/mqtt.js
index 683cfaf..007c644 100644
--- a/src/mqtt.js
+++ b/src/mqtt.js
@@ -721,6 +721,7 @@ client.on("message", async (topic, message) => {
                     || portnum === 66 // ignore RANGE_TEST_APP
                     || portnum === 72 // ignore ATAK_PLUGIN
                     || portnum === 257 // ignore ATAK_FORWARDER
+                    || portnum > 511 // ignore above MAX
                 ){
                     return;
                 }