What is the purpose of the 'TTL' field in IP packets?

The 'TTL' field in IP packets stands for 'Time to Live'. Its primary purpose is to specify the maximum number of hops a packet can make through routers on a network before it is discarded. This is important for preventing packets from circulating endlessly in the event of a routing loop. Each time a packet is forwarded by a router, the TTL value is decremented by one. If the TTL reaches zero, the packet is dropped, and typically, an error message is sent back to the sender indicating that the packet could not reach its destination. This mechanism helps maintain the efficiency of network traffic and prevents congestion caused by undeliverable packets.