During my last Building IPv6 Service Provider Core webinar I got a lot of questions about IPv6 over PPPoE (obviously we’re close to widespread IPv6 implementation; I never got PPPoE questions before). I wanted to test various scenarios in my IPv6 lab and thus enabled PPPoE on an Ethernet link between CE and PE routers.

This time I wanted to test multiple configurations in parallel ... no problem thanks versatile PPPoE implementation in Cisco.

On the server:

• Define multiple PPPoE server groups bound to different virtual templates;
• Attach a PPPoE server group to a VLAN subinterface;

On the client:

• Use multiple dialer pools to connect to different PPPoE servers over VLAN subinterfaces;
• Tie dialer interfaces to different dialer pools.

The relevant parts of the router configurations are included below:

PPPoE server configuration

bba-group pppoe SPA
 virtual-template 10
!
bba-group pppoe SPB
 virtual-template 20
!
interface FastEthernet0/0
 no ip address
 no shutdown
!
interface FastEthernet0/0.100
 encapsulation dot1Q 100
 pppoe enable group SPA
!
interface FastEthernet0/0.200
 encapsulation dot1Q 200
 pppoe enable group SPB
!
interface Virtual-Template10
 description *** Template for PPPoE group A (VLAN 100) ***
 mtu 1480
 ... 
!
interface Virtual-Template20
 description *** Template for PPPoE group B (VLAN 200) ***
 mtu 1480
 ... 

PPPoE client configuration

interface FastEthernet0/1
 no ip address
 no shutdown
!
interface FastEthernet0/1.100
 description *** PPPoE toward server group A ***
 encapsulation dot1Q 100
 pppoe-client dial-pool-number 1
!
interface FastEthernet0/1.200
 description *** PPPoE toward server group B ***
 encapsulation dot1Q 200
 pppoe-client dial-pool-number 2
!
interface Dialer1
 mtu 1480
 no ip address
 encapsulation ppp
 dialer pool 1
 dialer-group 1
 ...
!
interface Dialer2
 mtu 1480
 ip address negotiated
 encapsulation ppp
 dialer pool 2
 dialer-group 2
 ...

And the IPv6 support over PPPoE? Works surprisingly well. I was able to configure IPv6 autoconfiguration (each virtual access interface gets a /64, DHCP is used to propagate the DNS information) and prefix delegation with DHCP (virtual access interface remains unnumbered, a /64 is delegated to the CPE router via DHCP). The only task left: writing a follow-up report for my attendees.