Any routing protocol needs to solve the loop problem first. The OSPFISIS uses the SPF algorithm to solve the problem. The EIGRP algorithm is novel and is a diffusion algorithm. Therefore, BGP uses many small methods in the design, design diversified control attributes in energy refinement.
There are two BGP ring protection mechanisms:
1.The first is the internal ring protection of the AS. IBGP split horizon is implemented. The basic idea of IBGP split horizon is not to transmit the routes learned from IBGP peers to other IBGP peers.
2.The second is the ring protection between ASs. It is implemented through the AS-PATH attribute. The basic idea is as follows: If the AS_PATH of a route received by a BGP router from its external peer contains its own AS number, the router knows that a loop occurs and discards the route.
