"Secure VPN Connection terminated by Peer. Reason 433: (Reason Not Specified by Peer)"
Steps to resolve the issue
1. In order to resolve this issue, enable NAT Traversal (NAT-T) or IPsec over User Datagram Protocol (UDP) on the VPN Concentrator.
2. Allow the multiple connections from same NAT/PAT address by issuing the following command in PIX:
-- "isakmp nat-t"