diff --git a/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/CommunityIdProcessor.java b/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/CommunityIdProcessor.java
index f37fcf46979dc..926710a87832a 100644
--- a/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/CommunityIdProcessor.java
+++ b/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/CommunityIdProcessor.java
@@ -229,11 +229,11 @@ private static Flow buildFlow(
         switch (flow.protocol.getType()) {
             case Tcp, Udp, Sctp -> {
                 flow.sourcePort = parseIntFromObjectOrString(sourcePort.get(), "source port");
-                if (flow.sourcePort < 1 || flow.sourcePort > 65535) {
+                if (flow.sourcePort < 0 || flow.sourcePort > 65535) {
                     throw new IllegalArgumentException("invalid source port [" + sourcePort.get() + "]");
                 }
                 flow.destinationPort = parseIntFromObjectOrString(destinationPort.get(), "destination port");
-                if (flow.destinationPort < 1 || flow.destinationPort > 65535) {
+                if (flow.destinationPort < 0 || flow.destinationPort > 65535) {
                     throw new IllegalArgumentException("invalid destination port [" + destinationPort.get() + "]");
                 }
             }
@@ -268,7 +268,7 @@ static byte[] toUint16(int num) {
      */
     private static int parseIntFromObjectOrString(Object o, String fieldName) {
         if (o == null) {
-            return 0;
+            return -1;
         } else if (o instanceof Number number) {
             return number.intValue();
         } else if (o instanceof String string) {
diff --git a/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/CommunityIdProcessorTests.java b/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/CommunityIdProcessorTests.java
index 72771275743b0..be39a0a802020 100644
--- a/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/CommunityIdProcessorTests.java
+++ b/modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/CommunityIdProcessorTests.java
@@ -83,7 +83,7 @@ public void testBeatsInvalidSourceIp() {
     public void testBeatsInvalidSourcePort() {
         @SuppressWarnings("unchecked")
         var source = (Map<String, Object>) event.get("source");
-        source.put("port", 0);
+        source.put("port", -1);
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> testProcessor(event, null));
         assertThat(e.getMessage(), containsString("invalid source port"));
     }
@@ -302,9 +302,9 @@ public void testInvalidPort() {
         event = buildEvent();
         @SuppressWarnings("unchecked")
         var source = (Map<String, Object>) event.get("source");
-        source.put("port", 0);
+        source.put("port", -1);
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class, () -> testProcessor(event, null));
-        assertThat(e.getMessage(), containsString("invalid source port [0]"));
+        assertThat(e.getMessage(), containsString("invalid source port [-1]"));
 
         event = buildEvent();
         @SuppressWarnings("unchecked")
@@ -316,9 +316,9 @@ public void testInvalidPort() {
         event = buildEvent();
         @SuppressWarnings("unchecked")
         var source3 = (Map<String, Object>) event.get("destination");
-        source3.put("port", 0);
+        source3.put("port", -1);
         e = expectThrows(IllegalArgumentException.class, () -> testProcessor(event, null));
-        assertThat(e.getMessage(), containsString("invalid destination port [0]"));
+        assertThat(e.getMessage(), containsString("invalid destination port [-1]"));
 
         event = buildEvent();
         @SuppressWarnings("unchecked")