Its appears Windows 7 Firewall (32-bit) is blocking inbound UDP traffic and it is causing the Cisco VPN connection to drop. We have create new rules to allow outbound/inbound traffic on port 500 and enabled ForceNAT-T parameters, but the connection still drops. Any recommendations? I have attached the lastest log.
The logs shows the inbound UDP drops. But the TCP sent and receive works fine. We can try TCP ecapsulation of IPSec and ISAKMP packets. If it's not mandatory for you to use UDP then make sure you enable it on both ends (client and headend device).
Router: crypto isakmp ctcp port
ASA: crypto isakmp ipsec-over-tcp
Found this link, may be of your help in changing the policies of Windows firewall,