The policies shown below from the configuration of an Nokia 7750 SR have been created to implement an Extranet VPRN between the main sites of two…

To create an Extranet VPRN, routes from a specific site in one VPRN are selectively "leaked" to another VPRN. This is achieved by applying a route policy to the BGP export process on the PE router connected to the source site (Customer 1's main site). This export policy matches the routes from the main site and adds the Route Target (RT) community of the destination VPRN (Customer 2). When MP-BGP advertises these routes, they now carry the RT that allows Customer 2's VPRN to import them. Applying the policy only to the PE connected to the main site ensures that routes from other, non-extranet sites of Customer 1 remain private.

B. This describes the correct action for the PE at Customer 2's site using "ample Policy 3", not the correct application for "ample Policy" at Customer 1's site.

C. Policies are specific to each side of the extranet. Applying the same policy ("ample Policy 3") to both PEs would be incorrect as each needs to add a different RT.

D. Similar to option C, applying the same policy ("ample Policy") to both PEs is incorrect because each policy must be tailored to its specific VPRN and target.

E. Applying the policy to all PEs for Customer 1 would leak routes from all of its sites, violating the requirement to connect only the main sites.

1. Nokia 7750 SR OS Services Architecture Guide, Release 21.10.R1 (Document ID: 3HE 17176 AAAC TQZZA, Edition 01)

Section: VPRN Services > VPRN Extranet

Quote/Paraphrase: The guide states, "On the PE router that is attached to the extranet site, a BGP export policy is configured that adds the route target of the other VPRN to the routes that are advertised from the extranet site." This directly supports applying a specific export policy on the PE connected to the main site (Option A) and invalidates applying it to all sites (Option E). The configuration examples also show distinct policies for each side of the extranet, invalidating options C and D.