PPPoE is defined as Point-to-Point Protocol over Ethernet it is a protocol used for authentication in a DSL connection to an ISP or the Internet Service Provider.
The PPPoE uses a dialer called Virtual Lan Interface together with the physical WAN interface. This dialer will be used to configure the outside NAT, WAN access list and other WAN parameters in the physical WAN interface. The DSL using PPPoE primarily needs username and password for authentication.
2 Types of Authentication
CHAP – Challenge Handshake Authentication Protocol is the most commonly used authentication method by ISP and is more secure because it uses encryption to keep DSL password secure.
PAP – Password Authentication Protocol is an authentication method which sends information in a clear text.
The PPPoE requires at least 8 bytes from each data frame to carry PPP information and can be modified through the MTU size or the Maximum Transimission Unit of the dialer interface.