Mar 11, 2019

I have tried ip nat inside source static udp 192.168.xxx.xxx 500 interface Fa0/0 500 for all three ports (500/1701/4500) needed for L2TP, but I cannot seem to connect. Any advice would be appreciated. How to configure an L2TP/IPsec server behind a NAT-T Therefore, if the virtual private network (VPN) server is behind a NAT device, a Windows Vista-based VPN client computer or a Windows Server 2008-based VPN client computer cannot make a Layer Two Tunneling Protocol (L2TP)/IPsec connection to the VPN server. How to configure L2TP VPN on a Ubiquiti firewall

Dec 15, 2017

L2TP Ports - social.technet.microsoft.com Dec 24, 2012 What Ports To Open for L2TP VPN | Kuhnline.com

I am trying to set up IPSec/L2TP in Remote and Routing Service in Windows 2008 R2 Server. As I understand it, I need to do two things with respect to ports: (1) IPSec requires UDP port 500 and protocols 50 & 51 (IPSec passthrough) (2) L2TP requires UDP 1701, UDP 500 if using IPSec, UDP 4500 if using NAT-T, and L2TP pass through.

How to configure an L2TP/IPsec server behind a NAT-T Therefore, if the virtual private network (VPN) server is behind a NAT device, a Windows Vista-based VPN client computer or a Windows Server 2008-based VPN client computer cannot make a Layer Two Tunneling Protocol (L2TP)/IPsec connection to the VPN server.