DirectAccess feature IP-HTTPS only requirements?

Hi guys,

I try to set up a test environment for the direct access feature which comes with Windows 7 and Server 2008 R2. There's already a very good "step by step" guide available, but I'm very confused about the real requirements for this feature.

In the first step I simply want to replace a current VPN solution to get rid of the firewall dependencies.

My plan is:

- using IP-HTTPS only, anything else is blocked by firewall anyway.

- only using IPv6 where it is really necessary

- realizing an end to edge solution, not an end to end solution for the network

- not using IPv6 for the internal network, only for the direct access server.

My problem is that all guides I could find are describing a szenario where IP-HTTPS is used as a fallback solution and I'm not sure if I need things like two public IPv4 addresses (a little bit crazy anyway).

So some questions:

- Do I really need two public IPv4 addresses to realize direct access with IP-HTTPS only?

- Is it enough to use the direct access server als an ISATAP router and active IPv6 only on this server?

- Do I have to enable IPv6 on my internal DHCP server or on other internal servers except the direct access server?

- Is it possible to place a direct access server behind an existing ISA 2004 or ISA 2006 server or is TMG really needed?

I hope this is the right forum for this questions.

Regards & nice weekend,

MagicMight