Merge pull request #280742 from cfields475/patch-20

Update route-maps-about.md

Author: v-shils

articles/virtual-wan/route-maps-about.md

@@ -58,13 +58,15 @@ Before using Route-maps, take into consideration the following limitations:
 * When adding ASNs to the AS-PAT, only use the Private ASN range 64512 - 65535, but don't use ASN's Reseverd by Azure:
   * Public ASNs: 8074, 8075, 12076
   * Private ASNs: 65515, 65517, 65518, 65519, 65520
+* When using Route-maps, do not remove the Azure BGP communities:
+  *  65517:12001 , 65517:12002 , 65517:12003 , 65517:12005 , 65517:12006 , 65518:65518 , 65517:65517 , 65517:12076 , 65518:12076 , 65515:10000 , 65515:20000
 * You can't apply Route-maps to connections between on-premises and SD-WAN/Firewall NVAs in the virtual hub. These connections aren't supported during Preview. You can still apply route-maps to other supported connections when an NVA in the virtual hub is deployed. This doesn't apply to the Azure Firewall, as the routing for Azure Firewall is provided through Virtual WAN [routing intent features](how-to-routing-policies.md).
 * Route-maps supports only 2-byte ASN numbers.
 * The point-to-site (P2S) Multipool feature isn't currently supported with Route-maps.
 * Modifying the *Default* route is only supported when the default route is learned from on-premises or an NVA.
 * A prefix can be modified either by Route-maps, or by NAT, but not both.
 * Route-maps won't be applied to the [hub address space](virtual-wan-site-to-site-portal.md#hub).
-* Applying Route-Maps on NVAs in a spoke VNet is not supported. 
+* Applying Route-Maps on NVAs in a spoke VNet isn't supported. 
 
 ## Configuration workflow
 
@@ -101,7 +103,7 @@ Route-maps allows you to match routes using Route-prefix, BGP community, and AS-
 
 Match conditions are used to select a set of routes. Once those routes are selected, they can be dropped or modified. You can configure the following **Actions**:
 
-* **Drop:** All the matched routes are dropped (i.e filtered-out) from the route advertisement. For example, a site-to-site VPN connection has routes 10.2.1.0/24, 10.2.2.0/24 and 10.2.3.0/24 being advertised from Azure to a branch office. A route-map can be configured to drop 10.2.1.0/24, 10.2.2.0/24, resulting in only 10.2.3.0/24 being advertised from Azure to a branch office.
+* **Drop:** All the matched routes are dropped (i.e. filtered-out) from the route advertisement. For example, a site-to-site VPN connection has routes 10.2.1.0/24, 10.2.2.0/24 and 10.2.3.0/24 being advertised from Azure to a branch office. A route-map can be configured to drop 10.2.1.0/24, 10.2.2.0/24, resulting in only 10.2.3.0/24 being advertised from Azure to a branch office.
 
 * **Modify:** The possible route modifications are aggregating route-prefixes or modifying route BGP attributes. For example, a site-to-site VPN connection has routes 10.2.1.0/24 with an AS Path of 65535 and a BGP community of 65535:100 being advertised from Azure to a branch office. A route-map can be configured to add the AS Path of [65535, 65005].