Cisco VPN Error 412 for Legacy VPN Client v5.0.0.07
Reason 412. The remote peer is no longer responding”. Means that the software VPN Client detected that the VPN server is not responding anymore and deleted the connection. It can be anything from IPSEC traffic being blocked by your upstream device, NAT Issues or simply misconfigured VPN Settings:
Once verifying that the Cisco VPN client is setup properly, there are a number of additional troubleshooting steps that can be undertaken to solve the problem(s) throwing the error.
Step 1 – If the client computer is connecting to the Internet using a WiFi connection, try to connect using an Ethernet or USB connection. This will help eliminate the possibility that the WiFi connection is not providing sufficient connectivity.
Step 2 – Temporarily turn off the computer’s firewall and test the VPN connection. If the 412 error no longer occurs, then the cause of the error is needing to add firewall exception rules for the ESP protocol, port 500, and port 4500.
Step 3 – Enable or turn on the NAT-T/TCP option in your profile and ensure that port 10000 is unblocked in the computer’s firewall.
Step 4 – Update the ForceKeepAlive=0 to 1 in your profile.
Step 5 – If the VPN continues to throw the 412 error, then change the computer firewall settings to allow or permit UDP ports 500 and 62515 which are required for the Cisco VPN client.
Step 6 – Ensure the Cisco VPN client is actually sending data packets. To do so, open a console or command prompt window. Then, enter the command, “netstat –s –p ip 60” followed by pressing the “enter” key. This will let you see the IP end and receive packet counts.