Configuring PPPoE over ATM

Before you attempt to configure a PPPoE interface, configure the physical interface over which PPPoE traffic will flow. The procedure described in this topic assumes that a physical interface has been configured.

To configure PPPoE over ATM:

1. Configure a physical interface.
   host1(config)#interface atm 0/1
2. Configure the ATM 1483 subinterface.
   host1(config-if)#interface atm 0/1.20
3. Configure a PVC by specifying the vcd (virtual circuit descriptor), the vpi (virtual path identifier), the vci (virtual channel identifier), and the encapsulation type.
   host1(config-if)#atm pvc 10 22 100 aal5snap
4. Select PPPoE as the encapsulation method.
   host1(config-subif)#encapsulation pppoe

5. Do one of the following to configure the maximum number of PPPoE sessions (subinterfaces) supported on the interface:

   • Configure the maximum number of PPPoE sessions on a per-interface basis.
     host1(config-if)#pppoe sessions 128
   • Configure the maximum number of PPPoE sessions on a per-subscriber basis by overriding the current PPPoE maximum session value with the PPPoE maximum session value returned by the RADIUS server in the Max-Clients-Per-Interface vendor-specific attribute (VSA) [26-143] in Access-Accept messages.
     host1(config-if)#pppoe max-session-vsa override
6. Create a PPPoE subinterface.
   host1(config-subif)#interface atm 0/1.20.1
7. Select PPP as the encapsulation method.
   host1(config-subif)#encapsulation ppp
8. (Optional) Configure maximum transfer unit (MTU) parameters.
   host1(config-if)#pppoe mtu 1380
9. (Optional) Configure an access concentrator (AC) name on the PPPoE interface.
   host1(config-subif)#pppoe acname CYM9876
10. (Optional) Set up the router to prevent a client from establishing more than one session using the same MAC address.

    When the duplicate protection feature is enabled, multiple IWF PPPoE sessions that contain the same MAC address are still processed and can access network services until the maximum number of PPPoE sessions configured per major interface (configured using the pppoe sessions command) is reached. For more information about how IWF PPPoE sessions with duplicate addresses are handled, see Overview of IWF PPPoE Sessions with Duplicate MAC Addresses.

    host1(config-subif)#pppoe duplicate-protection
11. Assign an IP address and subnet mask to the PVC.
    host1(config-subif)#ip address 192.32.10.20 255.255.255.0
12. (Optional) Configure additional PPPoE subinterfaces by completing Steps 6 through 11 using unique numbering.
    host1(config-subif)#interface atm 0/1.20.2