Assigning IPv6 addresses from Cisco BRAS

A sample config for PPPoE clients connecting to a Cisco BRAS. The following example uses Stateless Address Autoconfiguration (SLAAC) to provide an IPv6 /64 subnet to clients on their PPP interface and DHCPv6 for Prefix Delegation in order to provide to a /56 subnet to them.

ipv6 unicast-routing
ipv6 general-prefix ISP-PREFIX 2001:DB8:BBBB::/48
ipv6 cef
ipv6 dhcp pool v6dhcppool
prefix-delegation pool v6prefixpool2
dns-server 2001:DB8:DDDD::1
dns-server 2001:DB8:EEEE::1
sip address 2001:DB8:CCCC::1
sip domain-name ipv6-test.example.com
Interface FastEthernet0/0.100
[ snip ]
ipv6 address ISP-PREFIX ::1:0:0:0:1/64
ipv6 enable
ipv6 mtu 1492
ipv6 nd reachable-time 30
ipv6 nd ra-interval 10
ipv6 nd ra-lifetime 3600
ipv6 nd prefix 2001:DB8:AAAA:2222::/64 86400 3600 off-link
ipv6 nd other-config-flag
ipv6 dhcp server v6dhcppool
!
Interface Virtual-Template1
[ snip ]
ipv6 unnumbered FastEthernet0/0.100
ipv6 enable
ipv6 mtu 1480
ipv6 nd reachable-time 30
ipv6 nd ra-interval 10
ipv6 nd ra-lifetime 3600
ipv6 nd prefix default infinite infinite off-link
ipv6 nd prefix 2001:DB8:BBBB:CCCC::/64 86400 3600 off-link
no ipv6 nd suppress-ra
ipv6 nd other-config-flag
ipv6 dhcp server v6dhcppool
peer default ipv6 pool v6prefixpool2
!
ipv6 local pool v6prefixpool 2001:DB8:9999:8800::/56 64
ipv6 local pool v6prefixpool2 2001:DB8:8888::/48 56

As the above config is just an example it uses the appropriate address space that IPv6 provides for examples, 2001:db8::/32

Hope it helps someone…