To facilitate managed central services in a Multiprotocol Label Switching (MPLS)-based network, DHCPv6 must be made MPLS-aware so that a single resource can be used to serve multiple VPNs instead of dedicating a resource to a single VPN.
The DHCPv6 server implementation of MPLS VPN allows a per-pool configuration so that DHCPv6 pools can be associated with a VPN routing and forwarding (VRF) instance. The DHCPv6 server differentiates clients from various VRFs and assigns an IPv6 prefix accordingly from the respective VRF pools. Meanwhile, the DHCPv6 bindings store the clients’ VRF information.
The DHCPv6 relay implementation allows the configuration of the destination VRF instance to which the relay messages will be forwarded. The relay adds the client’s VPN information while forwarding the client’s DHCPv6 requests toward the server, and the relay agent then processes the client’s VPN information in reply packets from the server.
The relay agent adds IPv6 static routes for delegated prefixes in corresponding clients’ VRF, and the relay agent’s high availability (HA) functionality synchronizes the VRF information while synchronizing static routes created by the relay process.
The DHCPv6 relay and server VRF-aware features are disabled by default.