Loops

Loops Routing loops are also called counting to infinity; there are several solutions.

Maximum Hop Count: RIP allows a maximum hop count of 15, a packet that needs 16 hop counts will be discarded.

Split Horizon: Data cannot be sent back in the direction that it came.

Poison Reverse: Won’t advertise out the same route it was learned.

Route Poisoning and Hold-Downs: Route table is updated when the route is unreachable, and hold-downs keep it from being updated more than once.

Triggered Updates: Routing table is sent once a topology chance has been made. They do not wait for the update timer to expire.