The Media Access Control (MAC) address of the peer is obtained during the Discovery stage of a Point-to-Point Protocol over Ethernet (PPPoE) session, not the Session stage. The Discovery stage is also sometimes called the Active Discovery stage. PPPoE sessions are divided into two distinct stages: the Discovery stage and the Session stage. Because an Ethernet host must first establish a connection to the remote peer before it can send data, the PPPoE Discovery stage must retrieve the MAC address of the remote peer and establish a Point-to-Point Protocol (PPP) session ID before establishing a PPP session.

Following the Discovery stage, the Session stage behaves mostly the same as a normal PPP session over a WAN link or dialup connection behaves. Therefore, the Session stage is also sometimes called the PPP Session stage. During the Session stage, PPP negotiates configuration options by sending Link Control Protocol (LCP) frames. Next, PPP sends out Network Control Protocol (NCP) frames to configure Network layer protocol information on the link and enable the link for packet traversal. The Session stage is also the stage in which PPP authentication occurs by using either Challenge Handshake Authentication Protocol (CHAP) or Password Authentication Protocol (PAP).