CompTIA Network+ Practice Test

What does the Network layer primarily use to route packets?

1. IP addresses

2. MAC addresses

3. TCP segments

4. Encryption keys

The correct answer is: IP addresses

The Network layer primarily uses IP addresses to route packets because it is responsible for logical addressing and path determination across interconnected networks. In this layer, each device on a network is assigned a unique IP address, which serves as the destination for data packets. This addressing allows devices on different networks to communicate with each other effectively, as the Network layer; specifically, protocols like Internet Protocol (IP) leverage these addresses to determine the best path for data to travel from the source to the destination. IP addresses are essential for routing because routers operate at the Network layer and make forwarding decisions based on these addresses. By analyzing the destination IP address contained within the packet, the router can consult its routing table to decide where to send the packet next. This function is necessary for facilitating communication across diverse networks, forming the backbone of the Internet and local area networks. In contrast, MAC addresses operate at the Data Link layer and are used for local frame delivery within a single network segment rather than across multiple networks. TCP segments relate to the Transport layer, where data segmentation, flow control, and error checking occur, while encryption keys are associated with security protocols and do not play a role in the routing of packets.