What is Cisco VPN Error 412?

This kind of error happens when the peer is not responding, and it occurs when using Cisco VPN client-side software. The error message, which may differ depending on which version of Cisco VPN client is in use, will typically read like, “Error Secure VPN Connection terminated locally by the Client. Reason 412: The remote peer is no longer responding”. Reasons for the cause of Cisco VPN Error 412 could be;

  1. There could be a firewall that is obstructing VPN traffic by blocking the ports UDP 4500/500 and/or ESP
  2. A sloppy connection which may precipitate packet not reaching the VPN concentrator or server. It could also be that the replies from the server are not reaching the client, making the client assume that the service is unavailable.
  3. It could also be that the VPN client is behind a NAT device but that the VPN server is not NAT-T enabled, in which case the user will neither send nor receive any data. If this persists for a while, the software client will erase the VPN tunnel.
  4. Another possibility could be that the VPN client is used to connect through TCP which now is blocked.

Once you establish that the reason for the error message is a firewall which is blocking the VPN traffic (and this usually happens when one is using Windows XP firewall), you can try to resolve this by configuring the firewall to permit UDP ports 500 and ESP which are required for Cisco VPN client. Alternately, you could try disabling any firewall that is installed on the PC, and once you have done that, try again and see if it works. Besides that, you could also try to confirm that the device that you are using is actually transmitting packets. To do this, start a cmd windows and key in the following command: ( netstat -s -p ip 60)

From there, you shall see the packets sent and received from the IP. In case your device is behind a NAT device as described in (3) above, try to resolve that by using an NAT-friendly VPN scheme. The default setting of IP/ESP does not work with many NAT devices. You can also use the following commands to have a glimpse of what is going on. You could try to ‘ping’ the remote peer and check on why they are not responding to the client.

C:Program FilesCisco SystemsVPN Clientvpnclient stat traffic

C:Program FilesCisco SystemsVPN Clientvpnclient stat tunnel

The problem can also be dealt with by removing and reapplying the crypto map on the interface to connect to the VPN. Also try setting the speed at around 100Mbps/Full duplex on the private interface. Also by setting your MTU to up to 1300 helps to prevent packets from being fragmented, this goes a long way toward increasing performance. Always ensure that the group name is identical to the VPN server group name. This can be done by going to “Start”, then to “All Programs” then to “Cisco Systems VPN Client”, and then to ” Set MTU’.

Additional Reading on Cisco VPN Error 412

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