When a packet reaches its TTL limit, what happens?

When a packet reaches its Time to Live (TTL) limit, it is discarded. The TTL is a mechanism used in networking to prevent packets from circulating indefinitely in the network. Each time a packet is forwarded by a router, its TTL value is decremented by one. When the TTL reaches zero, it indicates that the packet has exceeded its allowable hops, necessitating its removal from the network to maintain efficiency and prevent congestion.

This behavior is crucial for network stability, as it ensures that packets that can no longer reach their destination are not allowed to linger indefinitely. The packet is thus dropped instead of being continued to the next hop, rerouted to its origin, or sent back for reprocessing, which would not be an effective solution while managing network traffic. Discarding packets at their TTL limit helps maintain overall network performance and reliability.