rtadvd, dhcpv6, windows 7

[dandrzejewski]

Question here for everyone.

I've got my HE tunnel configured on my FreeBSD router.  I've got a Windows 7 machine.  Connectivity is actually perfectly fine, but here's a minor issue.

I've got rtadvd on the FreeBSD box set to send the M and O flags in the advertisement message.  I have verified with Wireshark that it is in fact sending the M and O flags. 

From what I've read in the RFCs, this means that the Windows 7 box should NOT try to do stateless auto configuration for anything other than the default gateway and route, and instead should look to DHCPv6 for everything else - including its local IP address.

Instead, the behavior I'm seeing is that the Windows 7 box DOES give itself an autoconfigured IP address based on that message, AND it also uses its DHCPv6-assigned address.

Is this the intended behavior?  I'd prefer to have all address assignments done through DHCPv6, because I want to do dynamic DNS and I really don't think it's necessary for anything on my network to have more than one IP address.

[cholzhauer]

FYI?

Code Select Expand


Managed Address Configuration Flag, which is also known as the M flag. When set to 1, this flag instructs the host to use a configuration protocol to obtain stateful addresses.

Other Stateful Configuration Flag , which is also known as the O flag. When set to 1, this flag instructs the host to use a configuration protocol to obtain other configuration settings.
Combining the values of the M and O flags can yield the following:

Both M and O Flags are Set to 0. This combination corresponds to a network without a DHCPv6 infrastructure. Hosts use router advertisements for non-link-local addresses and other methods (such as manual configuration) to configure other settings.

Both M and O Flags are Set to 1. DHCPv6 is used for both addresses and other configuration settings. This combination is known as DHCPv6 stateful, in which DHCPv6 is assigning stateful addresses to IPv6 hosts.

The M Flag is Set to 0 and the O Flag is Set to 1. DHCPv6 is not used to assign addresses, only to assign other configuration settings. Neighboring routers are configured to advertise non-link-local address prefixes from which IPv6 hosts derive stateless addresses. This combination is known as
DHCPv6 stateless: DHCPv6 is not assigning stateful addresses to IPv6 hosts, but stateless configuration settings.

The M Flag is Set to 1 and the O Flag is Set to 0. In this combination, DHCPv6 is used for address configuration but not for other settings. Because IPv6 hosts typically need to be configured with other settings, such as the IPv6 addresses of Domain Name System (DNS) servers, this is an unlikely combination.

Like DHCP for IPv4, the components of a DHCPv6 infrastructure consist of DHCPv6 clients that request configuration, DHCPv6 servers that provide configuration, and DHCPv6 relay agents that convey messages between clients and servers when clients are on subnets that do not have a DHCPv6 server.