nerdexam
Fortinet

NSE4 · Question #422

Which of the following IPsec configuration modes can be used when the FortiGate is running in NAT mode?

The correct answer is B. Both policy-based and route-based VPN. FortiGate appliances operating in NAT mode are fully capable of supporting both policy-based and route-based IPSec VPN configurations.

Submitted by andres_qro· Apr 18, 2026VPN and Routing

Question

Which of the following IPsec configuration modes can be used when the FortiGate is running in NAT mode?

Options

  • APolicy-based VPN only
  • BBoth policy-based and route-based VPN.
  • CRoute-based VPN only.
  • DIPSec VPNs are not supported when the FortiGate is running in NAT mode.

How the community answered

(31 responses)
  • A
    3% (1)
  • B
    87% (27)
  • C
    6% (2)
  • D
    3% (1)

Why each option

FortiGate appliances operating in NAT mode are fully capable of supporting both policy-based and route-based IPSec VPN configurations.

APolicy-based VPN only

While policy-based VPNs are supported in NAT mode, they are not the only type; route-based VPNs are also fully supported.

BBoth policy-based and route-based VPN.Correct

In NAT/Route mode, a FortiGate functions as a Layer 3 device, enabling it to establish both policy-based VPNs (controlled by firewall policies) and route-based VPNs (which use virtual tunnel interfaces and routing tables).

CRoute-based VPN only.

While route-based VPNs are supported in NAT mode, they are not the only type; policy-based VPNs are also fully supported.

DIPSec VPNs are not supported when the FortiGate is running in NAT mode.

IPSec VPNs are a core security feature and are widely supported and commonly deployed when a FortiGate is operating in its default NAT mode.

Concept tested: FortiGate IPSec VPN modes in NAT mode

Source: https://docs.fortinet.com/document/fortigate/7.4.0/administration-guide/603403/vpn-configuration

Topics

#IPsec VPN#VPN Modes#FortiGate NAT Mode#VPN Configuration

Community Discussion

No community discussion yet for this question.

Full NSE4 Practice