Test setup for AP 1142 and 18.104.22.168, have a 2106 running 22.214.171.124 with 1142 with two WLANs. Working OK but for VPN connections. See PPTP control messages between wireless client and VPN server up to the (Set-Link-Info), nothing after this from client off the 2106. On 4404s running 126.96.36.199, VPN works OK, see after the (Set-Link-Info) the GRE v1 tunnel being setup correctly.
Trying to verify this is a limitation of the 2106, not version 188.8.131.52? Release notes for 2106 say no support for (VPN termination such as IPsec and L2TP) but this seems to mean the 2106 is the end point, not just passing the connection?
I never got to the bottom of it. Cisco TAC guys helping me said Cisco VPN client worked fine in their lab testing, they did not have a MicroSoft VPN server to test with so no help for our setup. Must be something with the 21nn line, the 4404 I tested worked OK. The 2106 I had was just a demo unit, our production is 4404s so I left it go after testing OK on a 4404.