Connecting a local FortiGate to an AWS FortiGate via site-to-site VPN
This guide provides sample configuration of a site-to-site VPN connection from a local FortiGate to an AWS FortiGate via site-to-site IPsec VPN with static routing. You can access resources that are protected behind a FortiGate on AWS from your local environment by using a site-to-site VPN.
The following depicts the network topology for this sample deployment:
The following prerequisites must be met for this configuration:
- A FortiGate located on AWS with some resources behind it. In this example, the AWS FortiGate has port1 connected to WAN and port2 connected to local LAN.
- An on-premise FortiGate. For your local environment, determine if your FortiGate has a publicly accessible IP address or if it is behind NAT. In this example, the on-premise FortiGate is behind NAT.
This recipe consists of the following steps:
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- Create a VPN on the local FortiGate to the AWS FortiGate.
- Create a VPN on the AWS FortiGate to the local FortiGate.
- Establish a connection between the FortiGates.
To create a VPN on the local FortiGate to the AWS FortiGate:
- In FortiOS on the local FortiGate, go to VPN > IPsec Wizard.
- On the VPN Setup tab, configure the following:
- In the Name field, enter the desired name.
- For Template Type, select Site to Site.
- For Remote Device Type, select FortiGate.
- For NAT Configuration, select the appropriate option. In this example, since the local FortiGate is behind NAT, This site is behind NAT is selected. Click Next. For non-dialup situations where the local FortiGate has an external IP address, select No NAT between sites.
- On the Authentication tab, configure the following:
- For Remote Device, select IP Address.
- In the IP Address field, enter the AWS FortiGate's elastic IP address. In this example, it is 3.95.141.75.
- For Outgoing Interface, allow FortiOS to detect the interface via routing lookup.
- For Authentication Method, select Pre-shared Key.
- In the Pre-shared Key field, enter the desired key. Click Next.
- On the Policy & Routing tab, configure the following:
- For Local Interface, select the desired local interface. In this example, port2 is selected. The Local Subnets field should then auto-populate.
- In the Remote Subnets field, enter the remote subnet on the other side of the AWS FortiGate. In this example, it is 172.31.199.0/24.
- For Internet Access, select None.
- Click Create. The IPsec Wizard creates the following:
- Firewall addresses for local and remote subnets
- Firewall address groups containing the above firewall addresses
- phase-1 and phase-2 interfaces
- Static route and blackhole route
- Two firewall policies: one for traffic to the tunnel interface and one for traffic from the tunnel interface
To create a VPN on the AWS FortiGate to the local FortiGate:
- In FortiOS on the AWS FortiGate, go to VPN > IPsec Wizard.
- On the VPN Setup tab, configure the following:
- In the Name field, enter the desired name.
- For Template Type, select Site to Site.
- For Remote Device Type, select FortiGate.
- For NAT Configuration, select This site is behind NAT. This is the correct configuration since the AWS FortiGate has an elastic IP address. Click Next.
- On the Authentication tab, configure the following:
- For Incoming Interface, select the WAN-facing incoming interface. In this example, it is port1.
- For Authentication Method, select Pre-shared Key.
- In the Pre-shared Key field, enter the same key configured on the local FortiGate. Click Next.
- On the Policy & Routing tab, configure the following:
- For Local Interface, select the desired local interface. In this example, port2 is selected. The Local Subnets field should then auto-populate.
- In the Remote Subnets field, enter the remote subnet on the other side of the local FortiGate. In this example, it is 10.1.100.0/24.
- For Internet Access, select None.
- Click Create. The IPsec Wizard creates the following:
- Firewall addresses for local and remote subnets
- Firewall address groups containing the above firewall addresses
- phase-1 and phase-2 interfaces
- Static route and blackhole route
- Two firewall policies: one for traffic to the tunnel interface and one for traffic from the tunnel interface
To establish a connection between the FortiGates:
- The tunnels are down until you initiate a connection from the local FortiGate to the AWS FortiGate. In FortiOS on the local FortiGate, go to Monitor > IPsec Monitor.
- Right-click the phase-2 interface, and select Bring Up.
- In FortiOS on the AWS FortiGate, go to Monitor > IPsec Monitor and verify that the connection is up.
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The elastic IP address can be considered as one to one to the FortiGate's IP address, even though the port IP address may be an internal IP address. |