add ILB limitation

Author: halkazwini

articles/virtual-network/virtual-network-encryption-overview.md

@@ -6,7 +6,7 @@ ms.service: azure-virtual-network
 author: asudbring
 ms.author: allensu
 ms.topic: overview
-ms.date: 11/04/2024
+ms.date: 12/11/2024
 ms.custom: references_regions
 # Customer intent: As a network administrator, I want to learn about encryption in Azure Virtual Network so that I can secure my network traffic.
 
@@ -59,6 +59,8 @@ Azure Virtual Network encryption has the following limitations:
 
 - Virtual networks configured with the Azure Private Link service don't support Virtual Network encryption, so Virtual Network encryption shouldn't be enabled on these virtual networks. 
 
+- The backend pool of an internal load balancer must not include secondary IPv4 configurations on any of its network interfaces to prevent connection failures to the load balancer.
+
 - Virtual Network encryption shouldn't be enabled in virtual networks that have Azure confidential computing VM SKUs. If you want to use Azure confidential computing VMs in virtual networks where Virtual Network encryption is enabled, then:
 
     - Enable Accelerated Networking on the VM's NIC if it's supported.