Service targetPort guidance when customizing service's port

deploy-manage/deploy/cloud-on-k8s/accessing-services.md

@@ -68,7 +68,9 @@ You can expose services in [different ways](https://kubernetes.io/docs/concepts/
 By default, the {{es}} service created by ECK is configured to route traffic to all {{es}} nodes in the cluster. Depending on your cluster configuration, you may want more control over the set of nodes that handle different types of traffic (query, ingest, and so on). Refer to [](./requests-routing-to-elasticsearch-nodes.md) for more information.
 
 ::::{warning}
-When you change the `clusterIP` setting of the service, ECK will delete and re-create the service as `clusterIP` is an immutable field. Depending on your client implementation, this might result in a short disruption until the service DNS entries refresh to point to the new endpoints.
+When you change the `clusterIP` setting of the service, ECK deletes and re-creates the service, as `clusterIP` is an immutable field. Depending on your client implementation, this might result in a short disruption until the service DNS entries refresh to point to the new endpoints.
+
+If you change the service’s `port`, set `targetPort` to the container’s default listening port. Otherwise, Kubernetes uses the same value for both, resulting in failed connections. For reference, default ports are `9200` for the {{es}} HTTP interface, and `5601` for {{kib}}.
 ::::
 
 ```yaml subs=true

deploy-manage/deploy/cloud-on-k8s/requests-routing-to-elasticsearch-nodes.md

@@ -123,6 +123,9 @@ spec:
     elasticsearch.k8s.elastic.co/node-master: "false"
 ```
 
+:::{note}
+If you change the service’s `port`, set `targetPort` to `9200`, which is the default {{es}} HTTP interface port. Otherwise, Kubernetes uses the same value for both fields, resulting in failed connections.
+:::
 
 ## Specify a custom service in elasticsearchRef [k8s-traffic-splitting-with-service-name]
 

deploy-manage/security/k8s-transport-settings.md

@@ -30,7 +30,9 @@ spec:
 Check the [Kubernetes Publishing Services (ServiceTypes)](https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types) that are currently available.
 
 ::::{note}
-When you change the `clusterIP` setting of the service, ECK deletes and re-creates the service, as `clusterIP` is an immutable field. This will cause a short network disruption, but in most cases it should not affect existing connections as the transport module uses long-lived TCP connections.
+When you change the `clusterIP` setting of the service, ECK deletes and re-creates the service, as `clusterIP` is an immutable field. This causes a short network disruption, but it should not affect existing connections as the transport module uses long-lived TCP connections.
+
+If you change the service’s `port`, set `targetPort` to `9300`, which is the default {{es}} transport interface port. Otherwise, Kubernetes uses the same value for both, resulting in failed connections.
 ::::