DHCPv6 Behaviour in Windows Vista

Windows Vista introduces support for DHCPv6. The DHCPv6 client implementation in Windows Vista is compliant with RFC 3315. It supports 2 modes of operation: a stateless mode and a stateful mode of operation.


DHCPv6 Stateless mode is where the host uses a non-DHCPv6 method to obtain an IPv6 address, and uses DHCPv6 only to obtain other configuration parameters such as the IPv6 address of the DNS server. Typically in this mode, clients will use the IPv6 prefix from a Router Advertisement to auto-configure an IPv6 address for the network interface.


DHCPv6 Stateful mode is where a client uses DHCPv6 to obtain an IPv6 address from the DHCPv6 server along with other configuraiton parameters.


The DHCPv6 client mode of operation in Windows Vista is controlled by Router Advertisements. When the TCP/IP stack in Windows Vista receives a Media Connect event on a network interface, it sends a Router Solicitation. The Router Advertisement received in response determines the behaviour of the DHCPv6 client on that interface. If both the M & O flags in the Router Advertisement are set, the client assumes that it should DHCPv6 Stateful mode. If the O flag is set, but the M flag is not set, the DHCPv6 client uses the Stateless mode of operation.


Hope this helps you get started with deploying IPv6 in Windows Vista.


Santosh Chandwani

Windows Enterprise Networking


[This posting is provided "AS IS" with no warranties, and confers no rights.]