At a cooperative's aggregation router, a policy is applied where routes already sitting in the routing table are evaluated before Junos decides whether to advertise them out to an upstream transit provider. Which type of routing policy does this describe?

An export policy evaluates routes that are already present in the routing table and decides whether, and how, they are advertised out through a routing protocol to a neighbor, which matches the scenario of routes heading toward an upstream transit session. This is exactly the control point a rural cooperative needs to decide which subscriber aggregation prefixes get announced to a transit provider and which stay internal. An import policy is the reverse operation, filtering routes as they arrive from a protocol before installation into the table, so it cannot be the mechanism acting on routes that are already sitting there and about to leave. A login class restriction governs what commands and permissions a CLI user account is granted after authenticating, an access-control concept entirely separate from route advertisement. A configuration group is a Junos feature for reusing blocks of configuration across multiple statements or interfaces, and it has no involvement in deciding which routes get sent to a neighbor. A caveat worth remembering is that export policy cannot invent routes; it can only act on what is already active in the table, so a route that failed import or lost the best-path contest is never a candidate for export. A concrete check is show route advertising-protocol bgp <neighbor> <prefix>, which shows exactly what the export policy allowed out toward that peer.