Cisco VPN Error #433 -
"Reason Not Speficied by Peer."
Explanation: Another vague Cisco VPN error (usually from an ASA), that could mean a variety of things..
1. Check username/password (caps lock, etc..)
2. Check firewall settings on your laptop/desktop.. Are you blocking anything, any new GPO's deployed to your laptop from your Windows AD admin?
3. Enable Transparent Tunnelling in your VPN client to use IPSEC over UDP (possibly to get around a firewall blocked port on your laptop).
4. Any firewall changes on the router at your location (ie: new router, admin forgot to add in port openings? changes in the Nat? etc..)
5. Is this a reimaged laptop? Did you install the latest Cisco VPN client or an old version?
6. If you know the VPN admin at your company, ask him to look at the logs onthe ASA and maybe he can give you some insight on his end what he sees (ports, username mismatch, etc..)
Usually this error signifies something wrong on the client end, it may be vague, but check the laptop security settings or the router at your location.