Merge pull request #92561 from stevsmit/OCPBUGS-51092-udn-ir

Adds UDN IR limitation to UDN docs

Author: stevsmit

modules/nw-udn-limitations.adoc

@@ -22,4 +22,6 @@ While user-defined networks (UDN) offer highly customizable network configuratio
 
 * *Network policy limitations*: Network policies that enable traffic between namespaces connected to different user-defined primary networks are not effective. These traffic policies do not take effect because there is no connectivity between these isolated networks.
 
-* *Creation and modification limitation*: The `ClusterUserDefinedNetwork` CR and the `UserDefinedNetwork` CR cannot be modified after being created.
+* *Creation and modification limitation*: The `ClusterUserDefinedNetwork` CR and the `UserDefinedNetwork` CR cannot be modified after being created.
+
+* *Default network service access*: A user-defined network pod is isolated from the default network, which means that most default network services are inaccessible. For example, a user-defined network pod cannot currently access the {product-title} image registry. Because of this limitation, source-to-image builds do not work in a user-defined network namespace. Additionally, other functions do not work, including functions to create applications based on the source code in a Git repository, such as `oc new-app <command>`, and functions to create applications from an {product-title} template that use source-to-image builds. This limitation might also affect other `openshift-*.svc` services.