What is a split horizon technique used for in networking?

The split horizon technique is utilized primarily to prevent routing loops in computer networks. It operates on the principle that information about a route should not be sent back in the direction from which it was received. This approach effectively helps eliminate the possibility of a routing loop forming, which can occur when two routers continuously pass the same route information back and forth, causing confusion and inefficiency in the network.

By implementing split horizon, routers are restricted from advertising routes they learned from a particular interface back out of the same interface. This technique is particularly important in distance-vector routing protocols, since it helps maintain the integrity of routing tables and ensures that routers do not make erroneous decisions based on outdated or incorrect routing information.

The other options, while related to routing and networking concepts, do not accurately describe the specific purpose of split horizon. For instance, complete route advertising, improving bandwidth efficiency, and combining routes do not align with the core function of split horizon, which focuses on safeguarding the routing protocol from loops rather than enhancing the advertising process or bandwidth. Thus, the emphasis on preventing routing loops aligns precisely with the functionality of the split horizon technique.