What is NAT traversal in VPN FortiGate?

Network Address Translation (NAT) is a way to convert private IP addresses to publicly routable Internet addresses and vice versa. When the Nat-traversal option is enabled, outbound encrypted packets are wrapped inside a UDP IP header that contains a port number.

What is NAT traversal in IPSec?

NAT-T (NAT traversal or UDP encapsulation) makes sure that IPsec VPN connections stay open when traffic goes through gateways or devices that use NAT. When an IP packet passes through a network address translator device, it is changed in a way that is not compatible with IPsec.

How do I modify IPSec?

Select an IPsec tunnel and then select Edit to open the Edit VPN Tunnel page. Configure the following settings in the Edit VPN Tunnel page. After each editing a section, select the checkmark icon to save your changes.

What is IPSec DPD failure?

The IPSEC tunnel may fail when excessive Dead Peer Detection (DPD) messages are exchanged. This issue occurs when the following condition is met: Excessive DPD messages are exchanged.

What ports does IPSec use?

By default, IKEv2 uses IPSec, which requires UDP ports 500 and 4500, and ESP IP Protocol 50. You cannot disable IPSec. By default, L2TP uses IPSec, which requires UDP ports 500 and 4500, and ESP IP Protocol 50. If you disable IPSec, Mobile VPN with L2TP requires only UDP port 1701.

Why NAT traversal is required?

Nat Traversal, also known as UDP encapsulation, allows traffic to get to the specified destination when a device does not have a public IP address. This is usually the case if your ISP is doing NAT, or the external interface of your firewall is connected to a device that has NAT enabled.

How do I create a VPN policy?

Granular Routing Control

1. Find the best possible route for VPN traffic.
2. Select the interfaces that are used for VPN traffic to internal and external networks.
3. Configure the IP addresses that are used for VPN traffic.
4. Use route probing to select available VPN tunnels.

How do I configure IPsec?

To configure IPsec policies, select the desired IPsec policy, and then click [Change] to open the “IPsec Policy Settings” page. The following settings can be made on the “IPsec Policy Settings” page. No. Specify a number between 1 and 10 for the IPsec policy.

How do I bring IPSec tunnel in FortiGate?

To bring the VPN tunnel up, go to Monitor -> IPsec Monitor. Select ‘Status’ and select Bring Up.

How do I enable Nat on FortiGate?

Select Enable if a NAT device exists between the local FortiGate unit that is managed by a FortiProxy unit. and the VPN peer or client. The local FortiGate unit and the VPN peer or client must have the same NAT traversal setting (both selected or both cleared) to connect reliably.

How do I set up a VPN tunnel in FortiGate?

In the FortiGate, go to VPN > IP Wizard. Enter a Name for the tunnel, click Custom, and then click Next. Configure the Network settings. For Remote Gateway, select Static IP Address and enter the IP address provided by Azure. For Interface, select wan1.

How do I force IPsec to use NAT traversal?

Additionally, you can force IPsec to use NAT traversal. If this option is set to Forced, the FortiGate uses a port value of zero when constructing the NAT discovery hash for the peer. This causes the peer to think it is behind a NAT device, and it will use UDP encapsulation for IPsec, even if no NAT is present.

How to configure FortiGate logging for L2TP over IPsec?

Configuring FortiGate logging for L2TP over IPsec 1 Go to Log & Report > Log Settings. 2 Select Event Log. 3 Select the VPN activity event check box. 4 Select Apply. More