Configuring a Router as a PPPoE Client for DSL Connectivity Issue a show ip interface brief command on the Cust1 router to display the IP address assigned by the ISP router. Sample output is shown below. By what method was the IP address obtained? IPCP Reflection Question Why do ISPs who use DSL, primarily use PPPoE with their customers? PPPoE allows for easy separation of digital subscriber lines and allows ISPs to create pre-paid business models (such as DSL subscriptions) by allowing them to offer different speed tiers or Quality of Service bandwidth controls through a single DSL modem. PPPoE basically allows an ISP an easier way to track exactly how much bandwidth you are using in case they want to charge you for it in the future.