NAT Traversal in NGAF allows VPN traffic to pass through NAT devices by encapsulating the traffic in a way that preserves the original IP addresses, ensuring secure and reliable communication between endpoints.

In the NGAF (Network Gateway Appliance Firewall), NAT (Network Address Translation) traversal is a feature that enables IPsec traffic to pass through a NAT device, such as a router or a firewall, without breaking the IPsec connection. This is necessary because IPsec uses IP addresses and ports to establish and maintain secure connections, but these addresses and ports are often hidden by NAT devices.

When a NAT device is present between the two IPsec peers, it changes the source IP address of the packets to its own public IP address. However, this creates a problem for IPsec because the peer on the other side of the NAT device expects to see the original IP address of the sender. If the NAT device does not perform NAT traversal, the peer will not be able to establish a connection or authenticate the sender.

By performing NAT traversal, the NGAF ensures that IPsec traffic can pass through NAT devices without being blocked or broken, enabling secure connections between devices behind different NAT devices.

Hi, NAT traversal is key for making VPN connections work when you’re behind a NAT device like a router or firewall. VPNs, including Sangfor’s, use several methods to handle this, with NAT-T (NAT Traversal) being a popular one. NAT-T wraps VPN traffic in UDP packets to get through NAT devices, and it’s commonly used in IPSec VPNs. This helps systems behind NATs to set up secure connections on demand. Just remember, if your peer is using NAT traversal, you need to enable it too, or the connection won’t work.

HiHi,

Please find below the explanation of NAT-T:
NAT traversal is essential for enabling VPN connections when users are located behind a NAT device (such as a router or firewall) and need to establish a connection to the VPN server over the internet. Here are some common methods that VPN solutions, including Sangfor's, might use to address this challenge:

NAT-T (NAT Traversal): NAT-T is a standard technique that encapsulates VPN traffic within UDP packets to traverse NAT devices. Most modern VPN solutions support NAT-T, and it's often used in IPSec VPNs to enable communication through NAT gateways.

For additional VPN information, please refer to the link below:
hxx(tt)ps://community.sangfor.com/forum.php?mod=viewthread&tid=8981

Hi,

NAT traversal and IPsec may be used to enable opportunistic encryption of traffic between systems. NAT traversal allows systems behind NATs to request and establish secure connections on demand.

if your peer using nat traversal, you must enable also nat traversal, otherwise the connection can't established.