DHCPv6

DHCPv6 provider configuration. IANA pools, prefix delegation pools, and timing parameters are defined in IPv6 profiles, referenced by subscriber groups via ipv6-profile.

These settings apply to both IPoE and PPPoE subscribers. PPPoE carries Router Advertisements, Neighbor Advertisements and DHCPv6 (IA-NA + IA-PD) in-band over the PPP session, so a dual-stack PPPoE subscriber gets the same default route, address and delegated prefix as IPoE from the same configuration. The unicast knob below is IPoE-only: PPPoE is point-to-point, so periodic RAs always reach the single peer over the session.

Field	Type	Description	Example
provider	string	DHCPv6 provider: local	local
dns_servers	array	Global fallback IPv6 DNS servers	[2001:db8::53]
domain_list	array	DNS search domain list	[example.com]
ra	RA	Router Advertisement defaults

Modes

osvbng supports three DHCPv6 modes, selected per IPv6 profile:

Mode	Description
server	Local DHCPv6 server, allocates addresses and prefixes from configured pools (default)
relay	RFC 8415 relay agent, wraps client messages in Relay-Forward envelopes with Interface-ID, Remote-ID, and Subscriber-ID options
proxy	DHCPv6 proxy, relays to external servers but manages client-facing lifetimes independently

Mode is configured under ipv6-profiles.<name>.dhcpv6.mode. See IPv6 Profiles for the full configuration reference.

Router Advertisement

Default RA settings applied to subscriber sessions.

Field	Type	Description	Example
managed	bool	Set Managed (M) flag; indicates addresses are available via DHCPv6	true
other	bool	Set Other (O) flag; indicates other config (DNS, etc.) is available via DHCPv6	true
router_lifetime	int	Router lifetime in seconds advertised in RA; 0 means not a default router	1800
max_interval	int	Maximum interval in seconds between unsolicited RA messages	600
min_interval	int	Minimum interval in seconds between unsolicited RA messages	200
on_link	bool	Advertise the access prefix on-link (L flag). Default false: the prefix is off-link so subscribers route all traffic via the BNG; set true only for shared-LAN segments where subscribers reach each other directly	false
unicast	bool	Deliver periodic RAs as per-subscriber unicast (to the client link-local) rather than multicast ff02::1. Default true; falls back to multicast when the client link-local isn't yet known	true

Example

dhcpv6:
  provider: local
  dns_servers:
    - 2001:4860:4860::8888
    - 2001:4860:4860::8844
  ra:
    managed: true
    other: true
    router_lifetime: 1800
    max_interval: 600
    min_interval: 200

See IPv6 Profiles for relay and proxy configuration examples and DHCP Relay & Proxy for architecture details.