openshift-docs/modules/network-observability-working-with-udn.adoc

// Module included in the following assemblies:
//
// * network_observability/observing-network-traffic.adoc

:_mod-docs-content-type: PROCEDURE
[id="network-observability-working-with-udn_{context}"]
= Working with user-defined networks

[role="_abstract"]
Configure the `FlowCollector` custom resource to enable user-defined network (UDN) mapping, providing visibility into traffic across custom network interfaces within the web console.

You can enable user-defined networks (UDN) in network observability resources.
The following example shows the configuration for the `FlowCollector` resource.

.Prerequisite
* You have configured UDN in {openshift-networking}. For more information, see "Creating a UserDefinedNetwork by using the CLI" or "Creating a UserDefinedNetwork by using the web console."

.Procedure
. Edit the network observability `FlowCollector` resource by running the following command:
+
[source,terminal]
----
$ oc edit flowcollector
----

. Configure the `ebpf` section of the `FlowCollector` resource:
+
[source,yaml]
----
apiVersion: flows.netobserv.io/v1beta2
kind: FlowCollector
metadata:
  name: cluster
spec:
  agent:
    ebpf:
      sampling: 1  <1>
      privileged: true
      features:
      - UDNMapping
----
<1> Recommended so all flows are observed.

.Verification

* Refresh the *Network Traffic* page to view updated UDN information in the *Traffic Flow* and *Topology* views:

** In *Network Traffic* > *Traffic flows*, you can view UDNs under the `SrcK8S_NetworkName` and `DstK8S_NetworkName` fields.
** In the *Topology* view, you can set *Network* as *Scope* or *Group*.