Cisco Certified Network Associate (CCNA) Practice Exam 2026 - Free CCNA Practice Questions and Study Guide

The correct designations utilized with Port Aggregation Control Protocol (PAgP) are "Desirable" and "Auto." PAgP is a Cisco proprietary protocol used for automatically creating EtherChannels between switches.

In this context, "Desirable" allows a switch port to actively seek to form an EtherChannel, sending PAgP packets to negotiate the link. Conversely, "Auto" allows the port to participate in PAgP negotiations but does so passively, responding to desired PAgP packets from other switches. This negotiation process enables the formation of a bundled link that provides increased bandwidth and redundancy.

The other designations mentioned do not relate to the functions of PAgP. For instance, "Active and Backup" might suggest roles in a high-availability setup but do not represent PAgP states. Similarly, "Uplink and Downlink" refers to specific types of connections rather than PAgP negotiation modes, and "On and Off" is too vague and does not capture the negotiation dynamics inherent to PAgP.