Explanation https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/bbdsl/configuration/xe-3s/bba-xe-3s-book/bba-pppoe-client-x Restrictions for PPP over Ethernet Client The PPPoE client does not support the following: * More than ten clients per customer premises equipment (CPE) * Quality of service (QoS) transmission with queueing on the dialer interface * Dial-on-demand * Easy VPN * Native IPv6 * PPPoE client over ATM permanent virtual circuit (PVC) * Coexistence of the PPPoE client and server on the same device * Multilink PPP (MLP) on dialer interfaces * Nonstop forwarding (NSF) with stateful switchover (SSO)