Yes, it is possible to create a VPN between MikroTik and Fortinet devices. This setup allows you to establish a secure tunnel for network traffic between remote locations or between an office and the cloud, using common VPN protocols such as IPsec.

The process involves configuring both devices so that they understand each other and can exchange traffic securely. Here's an overview of how to do it:

1. Preparation

• VPN Parameter Agreement: Make sure both VPN ends (MikroTik and Fortinet) are configured with the same parameters for the IPsec tunnel, including encryption method, DH group, hash algorithm, pre-shared key (PSK), and any other parameters relevant.
• IP addresses: Defines the public IP addresses of both devices, which will be used to establish the tunnel. Additionally, it determines the internal networks (subnets) that will communicate through the VPN tunnel.

2. Settings in MikroTik

• IPsec Peer: Configure the IPsec peer on the MikroTik, specifying the IP address of the Fortinet device as the peer and the agreed parameters for phase 1 (IKE) and phase 2 (ESP) of IPsec.
• IPsec Policies: Establishes IPsec policies that define what traffic should be sent through the VPN tunnel, specifying the source and destination subnets.

3. Configuration in Fortinet

• IPsec Phase 1 and Phase 2: Configure IPsec phases 1 and 2 on the FortiGate, making sure the parameters match those configured on the MikroTik. This includes the pre-shared key, encryption and hashing algorithms, and DH pool configuration.
• Firewall Policies and Static Routes: Depending on your specific configuration and security policies, you will need to configure firewall policies to allow VPN traffic and possibly static routes to direct traffic through the tunnel.

4. VPN Tunnel Establishment

• Once both devices are configured, the tunnel should be established automatically as soon as there is traffic destined for the opposite subnet. You can check the tunnel status on both devices to make sure the VPN is up and working properly.

5. Testing and Monitoring

• Perform connectivity tests, such as pings, between subnets on both sides of the VPN tunnel to verify communication.
• Monitor the VPN tunnel on both devices to ensure it remains stable and to diagnose any issues that may arise.

Creating a VPN between MikroTik and Fortinet requires a detailed understanding of the VPN configurations on both devices, as well as adequate knowledge of networking and security concepts.

The official MikroTik and Fortinet documentation provides detailed guides and specific examples that can help you during the setup process.