Route Targets in VRF-Lite

A.

In a VRF-Lite implementation, a single physical router can support multiple virtual routing and forwarding (VRF) instances, allowing the router to support multiple independent routing tables. Route targets are used to control the import and export of routes into a customer routing table.

Option A: "Route targets control the import and export of routes into a customer routing table" is correct. In a VRF-Lite implementation, route targets are used to control the import and export of routes into a customer routing table. A route target is a special BGP extended community attribute that is used to identify a particular VRF instance, and its associated set of routes. By assigning a specific route target value to a VRF, the router can control which routes are imported and exported to/from that VRF.

Option B: "When BGP is configured, route targets are transmitted as BGP standard communities" is incorrect. While BGP is commonly used in conjunction with VRF-Lite, route targets are not transmitted as BGP standard communities, but rather as extended communities.

Option C: "Route targets allow customers to be assigned overlapping addresses" is incorrect. While VRF-Lite allows multiple customers to use the same IP address space without conflicting, this is achieved using separate VRF instances, not by route targets.

Option D: "Route targets uniquely identify the customer routing table" is incorrect. While route targets are used to identify a particular VRF instance, they do not uniquely identify the customer routing table as a VRF can contain multiple routing tables.

Therefore, the correct answer is option A: Route targets control the import and export of routes into a customer routing table.