Which of the following statements about the IP forwarding process on a router is TRUE?

The fundamental purpose of the IP forwarding process on a router is to determine the next hop for a packet on its path to the final destination. When a router receives an IP packet, it examines the destination IP address in the packet header. It then performs a lookup in its routing table to find the most specific, or longest prefix, match. This matching routing table entry provides the necessary information, such as the outgoing interface and the IP address of the next-hop router, to forward the packet correctly. This destination-based lookup is the core of the IP forwarding decision.

A. The forwarding decision is based on the packet's destination IP address, not its source. The source address is used for return traffic.

C. The ARP table maps IP addresses to MAC addresses; it is not used to look up a source MAC address for forwarding decisions.

D. The ARP table is used to find the next-hop MAC address only after the routing table lookup has already determined the next-hop IP address.

1. Nokia. (2021). Nokia Service Routing Architect (SRA) Self-Study Guide: IP/MPLS and Ethernet Services. Section: The IP Forwarding Process. This guide details that the primary step in IP forwarding is the lookup of the destination IP address in the routing table.

2. Kurose

J. F.

& Ross

K. W. (2021). Computer Networking: A Top-Down Approach (8th ed.). Pearson. Chapter 4

Section 4.2

"The Router". The text explicitly states

"the router forwards the datagram based on the datagram's destination address" and describes the process of consulting the forwarding table (routing table).

3. Nokia. (2022). SR OS R22.10.R1 Basic System Configuration Guide. Part: IP Routing

Section: Unicast Routing Overview. The documentation describes the forwarding plane's reliance on the routing table

which is populated by routing protocols

to make decisions based on destination prefixes.