Merge pull request #66003 from kquinn1204/OCPBUGS-19822

/lgtm OCPBUGS-19822 Additional Network and MetalLB cannot use same network

Author: JoeAldinger

modules/nw-metallb-infra-considerations.adoc

@@ -19,5 +19,4 @@ For example, the following infrastructures can benefit from adding the MetalLB O
 
 * {ibmpowerProductName}
 
-MetalLB Operator and MetalLB are supported with the OpenShift SDN and OVN-Kubernetes network providers.
-
+MetalLB Operator and MetalLB are supported with the OpenShift SDN and OVN-Kubernetes network providers.

modules/nw-metallb-layer2-limitations.adoc

@@ -34,3 +34,9 @@ The old node can continue to forward traffic for outdated clients until their ca
 
 During an unplanned failover, the service IPs are unreachable until the outdated clients refresh their cache entries.
 
+[id="additional_network_and_metallb_limitation_{context}"]
+== Additional Network and MetalLB cannot use same network
+
+Using the same VLAN for both MetalLB and an additional network interface set up on a source pod might result in a connection failure. This occurs when both the MetalLB IP and the source pod reside on the same node.
+
+To avoid connection failures, place the MetalLB IP in a different subnet from the one where the source pod resides. This configuration ensures that traffic from the source pod will take the default gateway. Consequently, the traffic can effectively reach its destination by using the OVN overlay network, ensuring that the connection functions as intended.