Announcing the general availability of Route-Maps for Azure virtual WAN.

Christopher-Fields

Microsoft

Apr 15, 2025

We are excited to announce the general availability of Route-Maps for Azure virtual WAN.

Route-maps is a feature that gives you the ability to control route advertisements and routing for Virtual WAN virtual hubs. Route-maps lets you have more control of the routing that enters and leaves Azure Virtual WAN site-to-site (S2S) VPN connections, User VPN point-to-site (P2S) connections, ExpressRoute connections, and virtual network (VNet) connections.

Why use Route-maps?

Route-maps can be used to summarize routes when you have on-premises networks connected to Virtual WAN via ExpressRoute or VPN and are limited by the number of routes that can be advertised from/to virtual hub.
You can use Route-maps to control routes entering and leaving your Virtual WAN deployment among on-premises and virtual-networks.
You can control routing decisions in your Virtual WAN deployment by modifying a BGP attribute such as AS-PATH to make a route more, or less preferable. This is helpful when there are destination prefixes reachable via multiple paths and customers want to use AS-PATH to control best path selection.
You can easily tag routes using the BGP community attribute in order to manage routes.

What is a Route-map?

A Route-map is an ordered sequence of one or more rules that are applied to routes received or sent by the virtual hub. Each Route-map rule comprises of 3 sections:

1. Match conditions

Route-maps allows you to match routes using Route-prefix, BGP community and AS-Path. These are the set of conditions that a processed route must meet in order to be considered as a match for the rule. Below are the supported match conditions.

Property	Criterion	Value (example)	Interpretation
Route-prefix	equals	10.1.0.0/16,10.2.0.0/16,10.3.0.0/16,10.4.0.0/16	Matches these 4 routes only. Specific prefixes under these routes won't be matched.
Route-prefix	contains	10.1.0.0/16,10.2.0.0/16, 192.168.16.0/24, 192.168.17.0/24	Matches all the specified routes and all prefixes underneath. (Example 10.2.1.0/24 is underneath 10.2.0.0/16)
Community	equals	65001:100,65001:200	Community property of the route must have both the communities. Order isn't relevant.
Community	contains	65001:100,65001:200	Community property of the route can have one or more of the specified communities.
AS-Path	equals	65001,65002,65003	AS-PATH of the routes must have ASNs listed in the specified order.
AS-Path	contains	65001,65002,65003	AS-PATH in the routes can contain one or more of the ASNs listed. Order isn't relevant.

2. Actions to be performed

Route-Maps allows you to Drop or Modify routes. Below are the supported actions.

Property	Action	Value	Interpretation
Route-prefix	Drop	10.3.0.0/8,10.4.0.0/8	The routes specified in the rule are dropped.
Route-prefix	Replace	10.0.0.0/8,192.168.0.0/16	Replace all the matched routes with the routes specified in the rule.
As-Path	Add	64580,64581	Prepend AS-PATH with the list of ASNs specified in the rule. These ASNs are applied in the same order for the matched routes.
As-Path	Replace	65004,65005	AS-PATH will be set to this list in the same order, for every matched route. See key considerations for reserved AS numbers.
As-Path	Replace	No value specified	Remove all ASNs in the AS-PATH in the matched routes.
Community	Add	64580:300,64581:300	Add all the listed communities to all the matched routes community attribute.
Community	Replace	64580:300,64581:300	Replace community attribute for all the matched routes with the list provided.
Community	Replace	No value specified	Remove community attribute from all the matched routes.
Community	Remove	65001:100,65001:200	Remove any of the listed communities that are present in the matched routes’ Community attribute.