Site to Site VPN & Nat Traversal - Cisco Community
ERROR IPSEC DROPPING PACKET: This means that the tunnel is not mounted and therefore can not transmit the traffic in the tunnel. AUTHENTICATION FAILED : This means that the extended authentication is activated on one of the two sides (see phase1, extended parameters) Automatic NAT Traversal for Auto VPN Tunneling between Automatic NAT Traversal Requirements. The UDP ports below are used by Automatic NAT traversal.When peers are directly connected to the Internet with a public IP address and not protected by a transparent firewall or when peers are behind a firewall and NAT that allow all outbound traffic and does not perform load balancing, no further configuration is necessary on upstream security systems. Site-to-site IPSec VPN through NAT - Packet Pushers May 03, 2017
Windows 7 IPSec/L2TP VPN connection problem
Configuration of an IPSec VPN Server on RV130 and - Cisco Dec 10, 2018
Automatic NAT Traversal Requirements. The UDP ports below are used by Automatic NAT traversal.When peers are directly connected to the Internet with a public IP address and not protected by a transparent firewall or when peers are behind a firewall and NAT that allow all outbound traffic and does not perform load balancing, no further configuration is necessary on upstream security systems.
May 03, 2017 Troubleshooting IPSec VPNs on Fortigate Firewalls Nov 12, 2019 NAT in a IPSEC VPN Tunnel | Fortinet Technical Discussion Jun 20, 2018 Windows 7 IPSec/L2TP VPN connection problem