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PPPoE Questions

February 6th, 2017 Go to comments

Question 1

Explanation

The picture below shows all configuration needed for PPPoE:

PPPoE_Topology_with_config.jpg

There is no Dialer interface on the PPPoE Server so answer “Dialer interface” is not correct. The most suitable answer is “Virtual Template” interface as it contains the pool which is used to assign IP address to the PPPoE Client. But this question is weird because according to the CCNAv3 syllabus, candidates only need to grasp the PPPoE on client-side, not sure why this question asked about PPPoE on Server side. For more information about PPPoE, please read our PPPoE tutorial.

Question 2

Explanation

PPPoE provides a standard method of employing the authentication methods of the Point-to-Point Protocol (PPP) over an Ethernet network. When used by ISPs, PPPoE allows authenticated assignment of IP addresses. In this type of implementation, the PPPoE client and server are interconnected by Layer 2 bridging protocols running over a DSL or other broadband connection.

PPPoE is composed of two main phases:
+ Active Discovery Phase: In this phase, the PPPoE client locates a PPPoE server, called an access concentrator. During this phase, a Session ID is assigned and the PPPoE layer is established.
+ PPP Session Phase: In this phase, PPP options are negotiated and authentication is performed. Once the link setup is completed, PPPoE functions as a Layer 2 encapsulation method, allowing data to be transferred over the PPP link within PPPoE headers.

Reference: http://www.cisco.com/c/en/us/td/docs/security/asa/asa92/configuration/vpn/asa-vpn-cli/vpn-pppoe.html

Question 3

Explanation

In the Dialer interface, we can use the “ip address negotiated” command to ask for an IP address from the PPPoE Server.

Comments (2) Comments
  1. silky
    February 17th, 2017

    regarding Q3. does the pppoe server act like a dhcp server? thanks

  2. lopwal
    February 22nd, 2017

    @silky. Yes it does PPPoE Server will provide IP address to the client. That is why you have to configure an IP Pool on server and the client IP is ‘negotiated’