fix(vpc): multiple default routes

Author: RoRoJ

pages/vpc/reference-content/understanding-routing.mdx

@@ -107,17 +107,19 @@ With new routing behavior, this standard behavior remains unchanged. Default rou
 
 However, you now have an additional option to enable each Private Network to receive advertisements of **all** default routes throughout the entire VPC. This includes routes towards all Public Gateways advertising a default route, as well as any custom-created default routes. This allows resources on other Private Networks to find access to the public internet, even if they do not have their own attached gateway.
 
-<Message type="note">
+See the [documentation](/vpc/how-to/manage-routing/#how-to-manage-default-route-scope) on how to manage default route scope for a given Private Network, once you have [updated](/vpc/how-to/manage-routing/#how-to-update-routing-behavior) to new routing behavior.
+
+#### Granularity
+
 The option to receive all default route advertisements must be enabled on a per-Private-Network basis. 
 
 This means that each Private Network in a VPC can opt to either receive **only** default routes from directly attached Public Gateways (and local custom default routes, if they exist), or **all** default routes being advertised throughout the whole VPC.
 
 If you wish to exercise more granular control over default route advertisements, we recommend that you configure [Network ACLs](/vpc/reference-content/understanding-acls) via the VPC API.
-</Message>
 
-TODO: add explanation about what happens when you're receiving multiple default route announcements?
+#### Multiple default routes
 
-See the [documentation](/vpc/how-to/manage-routing/#how-to-manage-default-route-scope) on how to manage default route scope for a given Private Network, once you have [updated](/vpc/how-to/manage-routing/#how-to-update-routing-behavior) to new routing behavior.
+When a resource on a Private Network receives multiple default route advertisements, the default route that is ultimately used will depend on the resource's OS and configuration. For a resource running Ubuntu, it is likely that the first default route advertisement received will be prioritized.
 
 ### Impact on existing setup