When will a VPN client identify itself as "Default Routing and Remote Access Class" to DHCP server?

Hi,

I set up a 3rd party pptp server and Windows server 2003 DHCP service, and I want to use user class "Default Routing and Remote Access Class" to assign additional options to VPN clients but failed.

The pptp server acts as a DHCP relay agent too.

I have checked client settings on Windows 7:

C:\Users\hayate>ipconfig /showclassid vpn

Windows IP Configuration


DHCPv4 Classes for Adapter "vpn":

   DHCPv4 ClassID Name . . . . . . . . : Default Routing and Remote Access Class

   DHCPv4 ClassID Description  . . . . : User class for remote access clients

   DHCPv4 ClassID Name . . . . . . . . : Default BOOTP Class
   DHCPv4 ClassID Description  . . . . : User class for BOOTP Clients

And used WireShark to capture the DHCP packet, then found that the client didn't use that id but "MSFT 5.0" to identify itself, so it of course failed.

So my question is, in what situation will the client use the "Default Routing and Remote Access Class"? Must I use RRAS server?

If I understand DHCP protocol correctly, the client directly communicates with DHCP server after establishing the tunnel, so I think the RRAS server is not necessary.

Thanks

Just Do It