Split Horizon Poison Reverse and Triggered Updates

Split Horizon, Poison Reverse, and Triggered Updates are all techniques used in distance vector routing protocols to prevent and resolve routing loops.

Split Horizon is a technique in which a router does not advertise a route back to the same interface from which it received that route. This prevents loops from occurring when a router advertises a route to a network through the same interface that it learned the route from.

Poison Reverse is a technique in which a router advertises a route back to the same router that sent it the route, but with an infinite metric. This tells the original router that the route is no longer valid and should be removed from its routing table.

Triggered Updates are updates that are sent immediately when a change in the network topology occurs, instead of waiting for the next scheduled update. This speeds up the convergence time of the routing protocol and helps to prevent loops. By using these techniques, distance vector routing protocols can more effectively prevent and resolve routing loops, improving the overall stability and performance of the network.