Fortinet FortiGate IPsec Configuration through CLI

Before you start

Overview

This article will show you how to use CLI to connect the FortiGate managed network to the Acreto Ecosystem.

Prerequisites

  1. FortiGate installation
  2. Ecosystem set up with proper security policies

How-To

Create Gateway for IPsec

This step is optional, skip it if you already own the Gateway.

Firstly, you will need to create a new Gateway device in the Acreto platform. Instructions on how to create a new Gateway are available here.

  1. Name: IPsec connection name must meet the same requirements as the Strongswan connection name (letters and numbers only).
  2. Category: IoT
  3. Type: IPsec
  4. Allow connection from: Empty (describes the source IP address where the IPsec connection will be permitted).
  5. Local Networks: any local network addresses that will be routed through this gateway. Wedge - New Gateway

To simplify testing, add the IP addresses of all interfaces connected to your gateway as Local Networks (you can use /32 prefix for public interface). This will allow you to test connectivity from the gateway through Acreto by using Ping, Traceroute, or similar tools.

Step 1: Read IPsec Gateway Values Required for Fortigate Configuration

To proceed with the Fortigate configuration, you will need a few values from an existing committed Acreto Gateway:

  1. Gateway Address
  2. Pre-Shared Key
  3. Recommended Ciphers

All of these may be found within the Gateway details panel - view the below animation for further instruction.

Animation how to get required values from Gateway [▶]

Step 2: Configure Fortigate - Create VPN (Phase1 and Phase2)

Use the following commands to create a VPN through CLI.

Log in to the Fortigate CLI.

  1. Configure IPsec VPN Phase-1

    config vpn ipsec phase1-interface
edit AcretoGate
 set interface <wan_interface>   
 set peertype any
 set net-device disable
 set mode-cfg enable
 set proposal aes128-sha256 aes256-sha512
 set ike-version 2
 set keylife 10800
 set remote-gw acreto-peer-ip       (Copy from Wedge Dashboard)
 set psksecret psk                  (Copy from Wedge Dashboard)
 set dhgrp 16
 set localid local-id              (Copy from Wedge Dashboard)
 next
end

  2. Configure IPsec VPN Phase-2

    config vpn ipsec phase2-interface
 edit AcretoGate
  set phase1name AcretoGate
  set proposal aes256-sha512 aes256gcm
  set dhgrp 16
  set keepalive enable
  set keylifeseconds 3600
 next
end

Step 3: Configure Fortigate - Create Address and Address group

  1. Create addresses for all local addresses/subnets

    config firewall address

edit AcretoGate_local_1
  set allow-routing enable
  set subnet 192.168.1.0 255.255.255.0
  next

edit AcretoGate_local_2             
  set allow-routing enable
  set subnet 192.168.2.0 255.255.255.0
  next
end

  2. Create an address group to add all the addresses created in the previous step

    config firewall addrgrp

edit AcretoGate_local_grp
 set member AcretoGate_local_1 AcretoGate_local_2
 next
end

Step 4: Configure Fortigate - Create Firewall Policy for Traffic

  1. Outbound Policy for traffic originating from Local lan interface to internet through Acreto VPN

    config firewall policy
edit 0
  set name Outbound_toAcreto 
  set srcintf lan_interface_ip 
  set dstintf AcretoGate
  set srcaddr AcretoGate_local_grp
  set dstaddr all
  set action accept
  set schedule always
  set service ALL
  next
end

  2. Inbound Policy for traffic coming from Acreto VPN to Local lan

    config firewall policy
edit 0
  set name Inbound_fromAcreto
  set srcintf AcretoGate
  set dstintf  lan_interface_ip
  set srcaddr all
  set dstaddr AcretoGate_local_grp
  set action accept
  set schedule always
  set service ALL
  next
end

Step 5: Configure Fortigate - Routing Changes

Scenario 1: When traffic from all local subnet/interfaces need to pass through the tunnel

  1. Add Static Route

    config router static
edit 0
 set dst Acreto_PeerIP
 set device wan_interface
 Set gateway ISP_Gateway       
 next
edit 0
 set dst 0.0.0.0 0.0.0.0
 set device AcretoGate
 set distance 4
 next
end

Scenario 2: When traffic from a specific subnet/interface needs to pass through the tunnel.

  1. Add IP at the tunnel interface

    config system interface
edit "AcretoGate"
 set ip 2.2.2.2 255.255.255.255
 set remote-ip 2.2.2.3 255.255.255.255
 next
end

  2. Add Static Route to direct the traffic through the tunnel with a higher administrative distance

    config router static
edit 0
 set distance 254
 set device AcretoGate
 set dst 0.0.0.0 0.0.0.0
 next
end

  3. Add Policy Route to direct the specific traffic through the tunnel

    config router policy
edit 0
 set input-device lan_interface 
 set srcaddr AcretoGate_local_grp
 set dstaddr all
 set output-device AcretoGate
 Set gateway 2.2.2.3
 next
end

Step 6: Configure Fortigate - Bring the Tunnel Up

Run the following command to bring the tunnel up bash diagnose vpn tunnel up AcretoGate

diagnose vpn tunnel up AcretoGate

Step 7: Configure Fortigate - Verify

  • Check the status of tunnel Phase-1
diagnose vpn ike gateway list name AcretoGate
  • Check status of Phase-2
diagnose vpn tunnel list name AcretoGate

Summary

Once the VPN connection is successfully established, all the internet traffic will be routed through Acreto.

Next page: Linux - Automatic IPsec Configuration