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.

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.

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.