IPv6 Dual-Stack
Native, RADIUS-driven IPv6 for every subscriber — delivered on the same session as their IPv4.
Overview
AthenaBNG terminates IPv6 alongside IPv4 for both access models:
- PPPoE — IPv6CP brings up the link, then addressing and delegation follow.
- IPoE / DHCP — SLAAC and DHCPv6 on the subscriber link, with Prefix Delegation for the home network.
There is no separate IPv6 stack to provision. A subscriber authenticates once, and the same RADIUS reply that drives their IPv4 session also describes their IPv6 addressing.
Addressing
| Plane | Mechanism | Typical size |
|---|---|---|
| WAN / subscriber link | Router Advertisements (SLAAC) + DHCPv6 (IA_NA) | /64 |
| Delegated LAN prefix | DHCPv6 Prefix Delegation (IA_PD) | /56 per subscriber |
IPv6 addressing is RADIUS-driven — the delegated prefix and WAN prefix come from your RADIUS server, not a local pool, so IPv4 and IPv6 assignment policy live in one place.
Dual-Stack Correlation
The key design point: IPv4 and IPv6 are one session, not two.
When a subscriber's IPv4 Access-Accept carries their delegated IPv6 prefix, AthenaBNG caches it against the access interface. The subsequent DHCPv6-PD exchange reuses that prefix rather than re-authenticating separately — so accounting, QoS, and the session lifecycle stay unified across both address families.
Routing
Delegated prefixes are redistributed into your IGP/EGP the same way IPv4 subscriber routes are. Upstream announcement is aggregate-only — the BNG advertises the covering block to your core (via iBGP and IS-IS) rather than leaking a route per subscriber.
Configuration
IPv6 is enabled per subscriber-facing interface and driven by RADIUS. A minimal dual-stack subscriber needs only the IPv6 attributes in its RADIUS profile (WAN prefix + delegated prefix); the data plane handles RA, DHCPv6, and PD automatically.
See the configuration guide for the full IPv6/dual-stack reference.