Aviatrix Gateway to FortiGate
Overview
This document describes how to configure an IPsec tunnel between an Aviatrix Gateway and a FortiGate firewall using Aviatrix Site2Cloud. This task is divided into two parts:
Configure a Site2Cloud tunnel in the Aviatrix Controller.
Configure a VPN tunnel and related components in the FortiGate Firewall.
Aviatrix Configuration
Adding a Site2Cloud tunnel in the Aviatrix Controller
Follow the steps in this guide.
Tip
Download the configuration to aid in the creation of the tunnel in FortiGate. The configuration can be downloaded from the Aviatrix Controller > Site2Cloud > Select the connection created earlier > Download Configuration. Select Generic for Vendor and Platform and Vendor independent for Software.
FortiGate Configuration
The configuration and screenshots below make the following three assumptions:
There are 2 interfaces on the FortiGate:
Interface port1 is an externally facing interface.
Interface port2 is an internally facing interface.
You have a subnet in AWS, Azure, or GCP in a VPC/VNet that has an Aviatrix Gateway. This subnet is defined as “10.0.0.0/16” for the examples below but it can be any valid CIDR range.
Note
In the examples below we refer to this range as AWS_Cloud.
You have a subnet behind your FortiGate firewall that will be accessible in the cloud. This subnet is defined as “172.16.0.0/20” in the examples below but it can be any valid CIDR range.
Note
In the examples below, we refer to this range as Shared_With_AWS.
Configuring Named Address Ranges in FortiGate
Access the FortiGate Dashboard, then, under Policy & Objects > Addresses, create two new addresses:
AWS_Cloud
Shared_With_AWS
Creating an IPsec Tunnel on FortiGate
Log in to the FortiGate and access the Dashboard.
In the VPN menu, select IPsec Wizard.
Change the Template Type to “Custom.”
Enter any value as the Name. For this example, we are using “ToAviatrixGW.”
Click Next >.
Fill out the Network fields as recommended below:
VPN Setup
Field
Expected Value
Name
Any Value
Template Type
Custom
Network
Field
Expected Value
IP Version
IPv4
Remote Gateway
Static IP Address
IP Address
Public IP address of Aviatrix Gateway
Interface
Select the Appropriate Port/Interface
Local Gateway
Disabled
Mode Config
Unmark this checkbox
NAT Traversal
Enable
Keepalive Frequency
Any value
Dead Peer Detection
On Demand
Forward Error Correction
Unmark this checkbox
Advanced Options
Disabled
Authentication
Field
Expected Value
Method
Pre-shared Key
Pre-shared Key
Enter the value from the downloaded configuration or the value typed in to the field in Aviatrix Site2Cloud
IKE Version
1
IKE Mode
Main (ID protection)
Phase 1 Proposal
Important
The following values from the Aviatrix Site2Cloud configuration are needed below:
In the Aviatrix Controller, select the Site2Cloud configuration created earlier.
Click next to Connect Detail.
Field
Expected Value
Encryption
Match value specified in Aviatrix S2C configuration (Phase 1 Encryption)
Authentication
Match value specified in Aviatrix S2C configuration (Phase 1 Authentication)
Diffie-Hellman Group
Match value specified in Aviatrix S2C configuration (Phase 1 DH Groups)
Key Lifetime (seconds)
28800
Local ID
Leave Blank
XAUTH
Field
Expected Value
Type
Disabled
Phase 2 Selectors
New Phase 2
Field
Expected Value
Name
Any String Value
Comments
Any String Value
Local Address
Named Address - Shared_With_AWS
Remote Address
Named Address - AWS_Cloud
Advanced
Important
The following values from the Aviatrix Site2Cloud configuration are needed below:
In the Aviatrix Controller, select the Site2Cloud configuration created earlier.
Click next to Connection Detail.
Click OK.
Configuring IPv4 Policy
In Policy & Objects, select IPv4 Policy. Create two new IPv4 policies:
Outbound traffic from FortiGate (Shared_With_AWS) to Aviatrix (AWS_Cloud)
Inbound traffic from Aviatrix (AWS_Cloud) to FortiGate (Shared_With_AWS)
Note
The reference to port2 in the screenshots should be replaced with your own interface name that represents the internal facing interface.
Note
Be sure to select accept for “action” and select all for “service.”
Adding a Static Route
From the FortiGate UI: navigate to Network > Static Routes , add a new static route for traffic destined to “AWS_Cloud” to use the VPN tunnel.
Note
If Named Address is disabled, be sure that you enabled Static Route Configuration on the Address configuration.
Bringing Up IPsec Monitor
From the FortiGate UI: In Monitor > IPsec Monitor, select the Aviatrix tunnel and click Bring Up.
Test
Once complete, test the communication using the tunnel.
Troubleshooting
Error Message
failed to get valid proposal
no suitable proposal found
Solution
Check that the Phase 1 authentication, encryption, and Diffie-Hellman groups match on both sides.
If you are experiencing low IPsec throughput, you may want to configure two commands on the Fortigate.
config system global
set ipsec-asic-offload disable
end
configure system global
set ipsec-hmac-offload disable
end