Configuring PPP and PPPoE Dynamic Interfaces

E-series routers support dynamic PPP and PPPoE interfaces. The configuration procedure is very similar for each.

When using the auto-configure command, select only ppp or pppoe. The router automatically builds the necessary interfaces for you. When you indicate pppoe, on receipt of a PPPoE packet, the dynamic interface built is IP over PPP over PPPoE over ATM. Likewise, when you indicate ppp, the dynamic interface built is IP over PPP over ATM.

Figure 25 shows dynamic PPP interface columns.

Figure 25: Dynamic PPP Interface Columns

Figure 26 shows dynamic PPPoE interface columns and illustrates how PPPoE permits multiple IP sessions over each ATM 1483 circuit.

Figure 26: Dynamic PPPoE Interface Columns

You can specify either or both ppp and pppoe for the interface by specifying the auto-configure command for each type of interface. The first packet received defines the type of dynamic interface that is created.

Configuring a PPP or PPPoE Dynamic Interface

To configure an ATM 1483 subinterface to support a dynamic PPP or PPPoE interface:

1. Configure a physical interface.

For ATM interfaces on ERX-7xx models, ERX-14xx models, and the ERX-310 router, use the slot/port format; for example:

host1(config)#interface atm 5/0 

2. Configure an ATM 1483 subinterface.

host1(config-if)#interface atm 5/0.1

3. Configure a PVC by specifying the virtual circuit descriptor (VCD), the virtual path identifier (VPI), the virtual channel identifier (VCI), and the encapsulation type.
   

   NOTE: If you want the router to autodetect the encapsulation type, use the aal5autoconfig option.

   
   

host1(config-subif)#atm pvc 10 100 22 aal5snap

host1(config-subif)#atm pvc 10 100 22 aal5autoconfig

4. Assign a profile to the PPP and/or PPPoE encapsulation types.

host1(config-subif)#profile ppp foo

host1(config-subif)#profile pppoe foobar

5. Configure the subinterface to recognize dynamic PPP and/or PPPoE.

host1(config-subif)#auto-configure ppp

host1(config-subif)#auto-configure pppoe

 NOTE: In addition, you can also specify ip or bridgedEthernet.



 

6. (Optional) Verify your configuration.

host1#show atm subinterface atm 5/0.1

atm pvc

• Use to configure a PVC on an ATM interface. Specify one of the following encapsulation types:

• aal5autoconfig—Enables autodetection of the 1483 encapsulation (LLC/SNAP or VC multiplexed).
• aal5snap—Specifies a logical link control (LLC) encapsulated circuit; the LLC/Subnetwork Access Protocol (LLC/SNAP) header precedes the protocol datagram.
• aal5mux ip—Specifies a VC multiplexed circuit. This option is used for IP only.

• Example

host1(config-subif)#atm pvc 6 0 11 aal5autoconfig

• Use the no version to remove the specified PVC.

auto-configure

• Use to configure an ATM subinterface to support a dynamic interface. Specifies the type(s) of dynamic encapsulation that will be accepted/detected by the ATM 1483 subinterface.
• This command makes the layers above ATM 1483 dynamic.
• Select the dynamic next upper-interface type from these options: bridgedEthernet, ip, ppp, or pppoe.
• You may enter the command repetitively to support multiple dynamic interface types.
• Example

host1(config-subif)auto-configure pppoe

• Use the no version to disable detection of the specified encapsulation.

interface atm

• Use to select an ATM interface or ATM 1483 subinterface.
• Use the slot/port[.subinterface ] format to select ATM interfaces on ERX-7xx models, ERX-14xx models, and ERX-310 routers.
• For more information, see Creating a Basic Configuration in Chapter 1, Configuring ATM.
• Example

host1(config)#interface atm 5/0.1

• Use the no version to remove the interface or subinterface.

profile

• Use to assign a profile.
• You must specify the encapsulation type to which the profile applies: bridgedEthernet, ip, ipv6, ppp, pppoe, or any.
• Specify a profile name with up to 80 characters.
• Example

host1(config-subif)#profile ppp foo

• Use the no version to remove a profile assignment.