Gateway-to-gateway configurations

Define the IPsec configuration

At each spoke, create the following configuration.

 

To define the Phase 1 parameters

1. At the spoke, go to VPN > IPsec Tunnels and create the new custom tunnel or edit an existing tunnel.

2. Edit the Phase 1 Proposal (if it is not available, you may need to click the Convert to Custom Tunnel button).

Enter the following information:

Name                                           Type a name, for example, toHub.

Remote Gateway                       Select Static IP Address.

IP Address                                 Enter 172.16.10.1.

Local Interface                          Select Port2.

Mode                                           Main

Authentication Method            Preshared Key

Preshared Key                          Enter the preshared key. The value must be identical to the preshared key that you specified previously in the FortiGate_1 configuration

Peer Options                             Select Any peer ID.

 

To define the Phase 2 parameters

1. Open the Phase 2 Selectors panel (if it is not available, you may need to click the Convert to Custom Tunnel button).

2. Enter the following information and select OK:

Name                                           Enter a name for the tunnel, for example, toHub_ph2.

Phase 1                                       Select the name of the Phase 1 configuration that you defined previously, for example, toHub.

Advanced                                   Select to show the following Quick Mode Selector settings.

Source                                        Enter the address of the protected network at this spoke.

For spoke_1, this is 10.1.1.0/24. For spoke_2, this is 10.1.2.0/24.

Destination                                Enter the aggregate protected subnet address, 10.1.0.0/16.

 

Define the security policies

You need to define firewall addresses for the spokes and the aggregate protected network and then create a security policy to enable communication between them.

 

To define the IP address of the network behind the spoke

1. Go to Policy & Objects > Addresses.

2. Select Create New and enter the following information:

Address Name                           Enter an address name, for example LocalNet.

Type                                            Subnet

Subnet/IP Range                       Enter the IP address of the private network behind the spoke.

For spoke_1, this is 10.1.1.0/24. For spoke_2, this is 10.1.2.0/24.

 

To specify the IP address of the aggregate protected network

1. Go to Policy & Objects > Addresses.

2. Select Create New and enter the following information:

Address Name                           Enter an address name, for example, Spoke_net.

Type                                            Subnet

Subnet/IP Range                       Enter the IP address of the aggregate protected network, 10.1.0.0/16.

 

To define the security policy

1. Go to Policy & Objects > IPv4 Policy and select Create New.

2. Leave the Policy Type as Firewall and leave the Policy Subtype as Address.

3. Enter the following information:

Incoming Interface                   Select the virtual IPsec interface, toHub.

Source Address                        Select the aggregate protected network address  Spoke_net.

Outgoing Interface                   Select the interface to the internal (private) network, port1.

Destination Address                 Select the address for this spoke’s protected network LocalNet.

Action                                         Select ACCEPT.

4. Select Create New.

5. Leave the Policy Type as Firewall and leave the Policy Subtype as Address.

6. Enter the following information, and select OK:

Incoming Interface                   Select the interface to the internal private network, port1.

Source Address                        Select the address for this spoke’s protected network, LocalNet.

Outgoing Interface                   Select the virtual IPsec interface, toHub.

Destination Address                 Select the aggregate protected network address, Spoke_net.

Action                                         Select ACCEPT.

Place these policies in the policy list above any other policies having similar source and destination addresses.

 

This entry was posted in FortiOS 5.4 Handbook and tagged , on by .

About Mike

Michael Pruett, CISSP has a wide range of cyber-security and network engineering expertise. The plethora of vendors that resell hardware but have zero engineering knowledge resulting in the wrong hardware or configuration being deployed is a major pet peeve of Michael's. This site was started in an effort to spread information while providing the option of quality consulting services at a much lower price than Fortinet Professional Services. Owns PacketLlama.Com (Fortinet Hardware Sales) and Office Of The CISO, LLC (Cybersecurity consulting firm).

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