What is the purpose of a routing protocol’s hop limit?

The purpose of a routing protocol's hop limit is primarily to prevent packets from endlessly circulating through a network. When a packet is transmitted, it is assigned a hop limit, which limits the number of intermediate devices (or hops) the packet can traverse before it is discarded. This mechanism is crucial for ensuring that packets do not get stuck in routing loops, where they keep circulating between routers without reaching their intended destination. By implementing a hop limit, networks can maintain efficiency and avoid potential congestion caused by overabundant traffic from such loops, which can degrade overall network performance.

The other options do not accurately represent the function of the hop limit. While routing may sometimes involve optimizing paths or managing bandwidth, these are separate considerations that do not directly relate to the purpose of the hop limit itself. The hop limit is specifically focused on packet lifecycle management—ensuring that packets have a clear end point and that the network operates smoothly without the risk of endless circulation.