Actually, I would like to allow users to use either the 64-bit Cisco VPN client or the Windows 7 built in client. Is this possible?
Additional information: The IOS host is the 881w-A-K9 ISR running version 15.1(4)M4.
There is no current VPN configuration.
Update 2015-02-06
I asked this question a year and a half ago, but I still do not have enough information to complete this task. I want to use the built-in L2TP/IPsec Windows client to dial-in to my router. The accepted answer to that question doesn't actually cover dial-in scenarios.
My immediate question is if this is even possible. It's hard for me to believe that it isn't, but this pages says:
Client-initiated tunnels using the L2TP or L2TPv3 protocol must be initiated by a router configured as the local peer. The L2TP and L2TPv3 protocols are not supported for client-initiated tunnels from a client PC.
However, this page, which is older, doesn't make any such warning. What is the authoritative answer to this question?