Update concepts-network-design-considerations.md

Clarify AS-prepend caveats for AVS

Author: adstuart

articles/azure-vmware/concepts-network-design-considerations.md

@@ -14,21 +14,20 @@ There are several networking considerations to review before you set up your Azu
 
 ## Azure VMware Solution compatibility with AS-Path Prepend
 
-Azure VMware Solution is compatible with AS-Path Prepend for redundant ExpressRoute configurations, with the caveat of not honoring the outbound path selection from Azure toward on-premises. If you're running two or more ExpressRoute paths between on-premises and Azure, and you don't meet the listed [prerequisites](#prerequisites), you might experience impaired connectivity or no connectivity between your on-premises networks and Azure VMware Solution. 
+Azure VMware Solution has considerations relating to the use of AS-Path Prepend for redundant ExpressRoute configurations, please consider the following guidance when needing to influence traffic out of Azure VMware Solution towards your On-Premises location via ExpressRoute GlobalReach, if you're running two or more ExpressRoute paths between on-premises and Azure.
 
-The connectivity problem happens when Azure VMware Solution doesn't notice AS-Path Prepend and uses equal-cost multipath (ECMP) routing to send traffic toward your environment over both ExpressRoute circuits. That action causes problems with stateful firewall inspection.
+Connectivity issues can occur, due to asymmetric routing, when Azure VMware Solution doesn't observe AS-Path Prepend and therefore uses equal-cost multipath (ECMP) routing to send traffic toward your environment over both ExpressRoute circuits. This behaviour can cause problems with stateful firewall inspection devices placed behind existing ExpressRoute circuits.
 
 ### Prerequisites
 
-For AS-Path Prepend, verify that all of the following listed connections are true:
+For AS-Path Prepend, please consider the following:
 
 > [!div class="checklist"]
+> * The key point is that you must prepend **Public** ASN numbers to influence how AVS route's traffic back to On-Premises. If you prepend using _Private_ ASN, AVS will ignore the prepend, and the ECMP behaviour above will occur. Please note that even if you operate a Private BGP ASN On-Premises, it is still possible to configure your On-Premises devices to utilises Public ASN when prepending routes outbound, to ensure compatibiliy with Azure VMware Solution.
 > * Both or all circuits are connected to Azure VMware Solution through ExpressRoute Global Reach.
 > * The same netblocks are being advertised from two or more circuits.
-> * Stateful firewalls are in the network path.
-> * You're using AS-Path Prepend to force Azure to prefer one path over others.
-
-Use either 2-byte or 4-byte public ASN numbers, and make sure that they're compatible with Azure VMware Solution. If you don't own a public ASN for prepending, open a [Microsoft support ticket](https://ms.portal.azure.com/#view/Microsoft_Azure_Support/HelpAndSupportBlade/~/overview) to view options.
+> * You wish to use AS-Path Prepend to force Azure VMware solution to prefer one circuit over another.
+> * Use either 2-byte or 4-byte public ASN numbers. If you don't own a public ASN for prepending, open a [Microsoft support ticket](https://ms.portal.azure.com/#view/Microsoft_Azure_Support/HelpAndSupportBlade/~/overview) to explore further options.
 
 ## Management VMs and default routes from on-premises