Pppoe configuration cisco pdf

To disable the effect of the minimum value, use the no form of this command. Optional Indicates that the value specified is a minimum. If a minimum value is specified, the echo request of that size is sent out on the Link Control Protocol LCP connection.

This command is entered under the virtual-template interface as a troubleshooting aid to verify the value for the negotiated MRU and to adjust the PPP virtual access interface MTU.

The failure of two such echo requests would be construed as the network not supporting that specific MTU. If a minimum value is configured, echo requests of that alternate size are sent out on the LCP connection.

If the minimum value is not configured, or if minimum echo requests also fail, then the PPP session is brought down. To remove this setting, use the no form of this command. The following is sample output from the show pppoe session command:. The following is sample output from the show pppoe session command when there is an IWF session and the ppp-max-payload tag is accepted in the discovery frame available in Cisco IOS Release Table 1 describes the significant fields shown in the displays.

To disable the effect of this command, use the tag p pp-max-payload deny command. Optional Specifies a minimum number of octets. The default minimum value is Optional Specifies a maximum number of octets. The default maximum value is Optional The minimum and maximum number depending on which keyword precedes the value in the command syntax of octets that can be accepted by the BRAS. Optional Disables the effect of any values previously entered with the tag ppp-max-payload command.

That is, the maximum accepted value of this tag from any client is limited to the minimum of physical interface MTU minus 8 and the maximum value configured by the tag ppp-max-payload maximum value. This maximum value cap set under the BBA group can be critical to network operation because the physical interface default MTU can be extremely high for example, octets for an ATM interface and the BRAS administrator may not want to negotiate such a high maximum receive unit MRU for a session.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature. Note See Internetworking Terms and Acronyms for terms not included in this glossary. Skip to content Skip to search Skip to footer. Available Languages. Download Options. Updated: December 5, These new interfaces are then configured automatically based on a template configuration known as a Virtual-Template.

The first step is to configure the virtual-template. Once a template has been configured, the next step is to configure a BBA group that will link to the Virtual-Template.

This configuration is as follows:. The final step is to bind this BBA group to the physical interface the server will listening for requests on. The configuration can be seen below. For those interested in taking the CCNA Routing and Switching exams then this configuration will be of interest as it is listed on the current blueprint. The dialer pool number is used to bind the dialer interface to the physical ethernet interface. This is important as the next step will reference the dialer pool number and not the interface number.

As soon as the final configuration goes in the Dialer interface should immediately come up and a virtual-access tunnel be built. The PPPoE session is now configured and traffic can now be transported across the point-to-point link. This next section reviews verification techniques that you can use to ensure a successful session was established and if not, help you to identify where the issue may lie. The first verification command is the debug ppp negotiation.

Debugging the negotiation will help you to see where the negotiation failed and why it may have failed. Remember that this output is only generated at the negotiation phase so you may need to flap the interface to cause this. Also, remember that the client is the one who initiated the connection so the shutdown should be done under the dialer interface. After the neogtiation is up, the next step would to verify that PPPoE specifically was established.

This can be done using the command show pppoe session. Should the session be up you can then verify layer 2 direct reachability via CDP. The final show command would be to view the routing table to ensure a host route has been installed for the remote side. The final verification for most technologies is a simple ping across to the other neighbour. This can be verified below:. Equally it allows a simple dynamic IP address to be allocated without the need for server to be located on the same subnet as the clients conserving the address usage.

Please also find attached a packet capture of the negotiation of PPPoE and the sending of traffic in the data-plane. Dec 1, 1 KB zip. Thanks for sharing, it explains very clear the topic. David P. A great overview about pppoe and pppoe configuration on cisco devices. Thank you. If you encounter a technical issue on the site, please open a support case. Communities: Chinese Japanese Korean. All Rights Reserved. The Cisco Learning Network. Information Author. Cisco Admin. Prerequisites An understanding of Ethernet operation and Switching functions An understanding of PPP negotiations An understanding of the OSI protocol stack and the layers Concepts PPPoE is a client and server initiation that functions similarly to dial up connections where clients dial in for a session when interesting traffic is required to be transmitted.

To better demonstrate this, below shows a frame format for PPPoE captured between two devices running an active session: As you can see, the payload is encapsulated with an IP header as you would expect which is then included inside a normal PPP frame header.

Configuration Without further ado, the following section will be going through the configuration of both the PPPoE server listening for dial in requests as well as the PPPoE client who will be initiating the session. In order to demonstrate this, the following topology is being used: 2 Routers are connected together via separate switches which are trunking between for all VLANs so common layer 2 reachability is obtained.

This configuration is as follows: The final step is to bind this BBA group to the physical interface the server will listening for requests on. That's it for the server. The configuration can be seen below: The dialer pool number is used to bind the dialer interface to the physical ethernet interface. Verification This next section reviews verification techniques that you can use to ensure a successful session was established and if not, help you to identify where the issue may lie.

Hope This Helps, Josh Kingsbury. Article Details Title.