Question

At every hop from a source to a destination, the TTL field in an IP protocol header is decremented. What happens if this field counts down to 0?

a) The packet is dropped
b) The packet is rerouted
c) The packet is duplicated
d) The packet is encrypted

Answer 1

In an IP protocol header, the TTL field is used to limit the lifespan of a packet. When the TTL field counts down to 0, the packet is dropped.

Step-by-step explanation:

In an IP protocol header, the TTL (Time to Live) field is used to limit the lifespan of a packet. At every hop from a source to a destination, the TTL value is decremented by one. When the TTL field counts down to 0, the packet is dropped. This mechanism ensures that packets do not circulate indefinitely in the network. It helps prevent packets from getting stuck in loops or congested areas, as well as helps limit the time taken by packets to reach their destination.

For example, if a packet with a TTL of 5 is sent from the source, at each hop, the TTL will be decremented. If it takes 3 hops to reach the destination, the TTL will become 2 by the time it reaches the destination. If it takes more than 5 hops and the TTL reaches 0, the packet will be dropped.