I had a couple of emails overnight asking whether it is possible to use Hyper-V Manager "v1" (as in KB952627 for Windows Vista SP1, or part of RSAT in Windows Server 2008) pointing to a machine running Windows Server 2008 R2 RC or Microsoft Hyper-V Server 2008 RC.
The short answer is yes, this works. The slightly longer (and intentionally non-exhaustive answer) is:
The first two points are somewhat obvious, but it's that last point I wanted to expand a little further on in this post.
If you're not familiar with a "dedicated" network (otherwise known as an External Virtual Network for which the management operating system is not allowed to share the network adapter), take a trip back to my post a couple of days ago. The "v1" UI only knows about External Virtual Networks which have a virtual NIC in the parent partition. When it sees an external switch without the parent virtual NIC, it assumes that manual intervention or scripting has taken place to alter the network in some way. Hence, it blocks you being able to change the network into an Internal or Private network.
Somewhat aside to this (but I only say it as I know I’ll get plenty of email from the diligent readership I have letting me know....), you may notice that when using the v1 UI for managing a dedicated network, the "Enable virtual LAN identification for parent partition checkbox if enabled. Further you can set the VLAN ID, click OK and won't see an error – it will appear to succeed. The operation itself is meaningless as there is no virtual NIC in the parent partition to apply the VLAN ID to - if you subsequently were to re-open Virtual Network Manager using the "v1" UI, you'd note that the change had not been applied. It simply a bug and is fixed in the "v2" UI.