Cisco Certified Network Associate (CCNA) Practice Exam

Which PPP function facilitates the automatic configuration of the serial link?

1. Dynamic Host Configuration Protocol (DHCP)

2. Link Control Protocol (LCP)

3. Network Control Protocol (NCP)

4. Address Resolution Protocol (ARP)

The correct answer is: Link Control Protocol (LCP)

The function that facilitates the automatic configuration of the serial link in the context of Point-to-Point Protocol (PPP) is the Link Control Protocol (LCP). LCP is responsible for establishing, configuring, and testing the data link connection. It manages the link setup and teardown processes, negotiating options such as maximum transmission unit (MTU) size and authentication methods. Through LCP, PPP can automatically configure the necessary parameters needed for a successful communication session over a serial link. This includes dynamically negotiating options that influence how data is encapsulated, ensuring that both ends of the point-to-point link operate efficiently and effectively. While other protocols like DHCP serve specific roles in network configuration and dynamic IP address assignment, they are not directly involved in the link layer's processing as it pertains to PPP. NCP, on the other hand, is responsible for network layer protocols but doesn’t handle link configuration. ARP operates at the network layer to resolve IP addresses to MAC addresses and is not relevant for the configuration of serial links under PPP.