L is a network design engineer. In a certain network project, in order to reduce the complexity, the small L design network adopts a two-layer architecture, and the access layer functions are incorporated into the convergence layer. In the design, the small L takes into account that the core layer needs to have a fast convergence function, and the convergence layer performs route aggregation to reduce the number of routes. Among the following routing protocols, which one should be used by Little L as the core layer routing protocol? (Choose one or more)