What mechanism do routers use to prevent IPv4 packets from circulating endlessly in a network?

What mechanism do routers use to prevent IPv4 packets from circulating endlessly in a network?

• A. It discards packets based on their size
• B. It increments the TTL field by 1
• C. It decrements the value of the TTL field and discards packets if TTL reaches zero
• D. It reroutes packets back to the source

Answer: (C)

Routers utilize the Time to Live (TTL) field in an IPv4 packet to prevent packets from circulating endlessly within a network. Each IPv4 packet includes a TTL value that is set when the packet is created. As the packet traverses through routers, each router decrements this TTL value by one. When the TTL value reaches zero, the router recognizes that the packet has exceeded its allowed lifespan in the network and subsequently discards it. This mechanism serves as a safeguard against routing loops, where packets could otherwise be endlessly forwarded among routers without reaching their destination. By discarding packets that have become too old, the network is protected from unnecessary traffic and potential congestion, maintaining overall network performance and efficiency.

Routers utilize the Time to Live (TTL) field in an IPv4 packet to prevent packets from circulating endlessly within a network. Each IPv4 packet includes a TTL value that is set when the packet is created. As the packet traverses through routers, each router decrements this TTL value by one.

When the TTL value reaches zero, the router recognizes that the packet has exceeded its allowed lifespan in the network and subsequently discards it. This mechanism serves as a safeguard against routing loops, where packets could otherwise be endlessly forwarded among routers without reaching their destination. By discarding packets that have become too old, the network is protected from unnecessary traffic and potential congestion, maintaining overall network performance and efficiency.