From 4f23847546981324568b24ac406e1cbd7631b200 Mon Sep 17 00:00:00 2001
From: Dave Conway-Jones <conway@uk.ibm.com>
Date: Thu, 16 Sep 2021 16:22:01 +0100
Subject: [PATCH] Fix UDP node to not not use port if unassigned

---
 packages/node_modules/@node-red/nodes/core/network/32-udp.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/node_modules/@node-red/nodes/core/network/32-udp.js b/packages/node_modules/@node-red/nodes/core/network/32-udp.js
index 894c19d77..d42d3a7c3 100644
--- a/packages/node_modules/@node-red/nodes/core/network/32-udp.js
+++ b/packages/node_modules/@node-red/nodes/core/network/32-udp.js
@@ -178,7 +178,7 @@ module.exports = function(RED) {
         var sock;
         var p = this.outport || this.port || "0";
         node.tout = setTimeout(function() {
-            if (udpInputPortsInUse[p]) {
+            if ((p != 0) && udpInputPortsInUse[p]) {
                 sock = udpInputPortsInUse[p];
                 if (node.multicast != "false") {
                     sock.setBroadcast(true);