Configure firewall policies

Oct 13, 2025 by leolavanderia.com.br 81 views

Introduction

Configuring a site-to-site IPsec VPN between two Fortigate routers can be a complex task, especially when it comes to ensuring that resources on one side of the VPN can be accessed from the other side. In this article, we will discuss the common issues that may arise when trying to access resources on the other side of a Fortigate site-to-site VPN and provide step-by-step troubleshooting guides to help you resolve these issues.

Understanding Site-to-Site VPN Configuration

Before we dive into troubleshooting, it's essential to understand the basic configuration of a site-to-site VPN on Fortigate routers. A site-to-site VPN is a type of VPN that allows two or more networks to communicate with each other securely over the internet. To configure a site-to-site VPN on Fortigate routers, you need to:

Create a VPN tunnel: This involves creating a secure connection between the two Fortigate routers using IPsec.
Configure firewall policies: You need to create firewall policies that allow traffic to flow between the two networks.
Configure static routes: You need to configure static routes on each Fortigate router to ensure that traffic is routed correctly between the two networks.

Common Issues with Site-to-Site VPN

Despite proper configuration, you may still encounter issues when trying to access resources on the other side of the VPN. Some common issues include:

Inability to access resources on the other side: You may not be able to access resources such as files, printers, or applications on the other side of the VPN.
Inability to ping or access the VPN gateway: You may not be able to ping or access the VPN gateway on the other side of the VPN.
Inability to establish a VPN connection: You may not be able to establish a VPN connection between the two Fortigate routers.

Troubleshooting Steps

To troubleshoot these issues, follow these step-by-step guides:

Step 1: Verify VPN Tunnel Status

Check VPN tunnel status: Log in to the Fortigate web interface and navigate to VPN > IPsec Tunnels. Verify that the VPN tunnel is up and running.
Check VPN tunnel logs: Check the VPN tunnel logs to see if there are any errors or issues that may be preventing the VPN tunnel from establishing.

Step 2: Verify Firewall Policies

Check firewall policies: Log in to the Fortigate web interface and navigate to Policy & Objects > Firewall Policy. Verify that the firewall policies are correctly configured to allow traffic to flow between the two networks.
Check firewall policy logs: Check the firewall policy logs to see if there are any errors or issues that may be preventing traffic from flowing between the two networks.

Step 3: Verify Static Routes

Check static routes: Log in to the Fortigate web interface and navigate to Network > Static Routes. Verify that the static routes are correctly configured to route traffic between the two networks.
Check static route logs: Check the static route logs to see if there are any errors or issues that may be preventing traffic from being routed correctly between the two networks.

Step 4: Verify VPN Gateway Configuration

Check VPN gateway configuration: Log in to the Fortigate web interface and navigate to VPN > IPsec Tunnels. Verify that the VPN gateway is correctly configured to allow traffic to flow between the two networks.
Check VPN gateway logs: Check the VPN gateway logs to see if there are any errors or issues that may be preventing traffic from flowing between the two networks.

Step 5: Verify Network Configuration

Check network configuration: Log in to the Fortigate web interface and navigate to Network > Interfaces. Verify that the network configuration is correctly set up to allow traffic to flow between the two networks.
Check network logs: Check the network logs to see if there are any errors or issues that may be preventing traffic from flowing between the two networks.

Conclusion

Configuring a site-to-site VPN on Fortigate routers can be a complex task, but with the right troubleshooting steps, you can resolve common issues and ensure that resources on one side of the VPN can be accessed from the other side. By following the step-by-step guides outlined in this article, you can troubleshoot and resolve issues related to site-to-site VPN configuration, firewall policies, static routes, VPN gateway configuration, and network configuration.

Additional Tips and Best Practices

Regularly monitor VPN tunnel status: Regularly monitor the VPN tunnel status to ensure that it is up and running.
Regularly check firewall policy logs: Regularly check firewall policy logs to ensure that there are no errors or issues that may be preventing traffic from flowing between the two networks.
Regularly check static route logs: Regularly check static route logs to ensure that there are no errors or issues that may be preventing traffic from being routed correctly between the two networks.
Regularly check VPN gateway logs: Regularly check VPN gateway logs to ensure that there are no errors or issues that may be preventing traffic from flowing between the two networks.
Regularly check network logs: Regularly check network logs to ensure that there are no errors or issues that may be preventing traffic from flowing between the two networks.

Q: What is a site-to-site VPN?

A: A site-to-site VPN is a type of VPN that allows two or more networks to communicate with each other securely over the internet. It is commonly used to connect two or more offices or locations that are separated by a large distance.

Q: What is the difference between a site-to-site VPN and a remote access VPN?

A: A remote access VPN is a type of VPN that allows individual users to access a network from a remote location. A site-to-site VPN, on the other hand, allows multiple networks to communicate with each other securely over the internet.

Q: How do I configure a site-to-site VPN on Fortigate routers?

A: To configure a site-to-site VPN on Fortigate routers, you need to:

Create a VPN tunnel: This involves creating a secure connection between the two Fortigate routers using IPsec.
Configure firewall policies: You need to create firewall policies that allow traffic to flow between the two networks.
Configure static routes: You need to configure static routes on each Fortigate router to ensure that traffic is routed correctly between the two networks.

Q: What are the common issues that may arise when trying to access resources on the other side of a Fortigate site-to-site VPN?

A: Some common issues that may arise when trying to access resources on the other side of a Fortigate site-to-site VPN include:

Inability to access resources on the other side: You may not be able to access resources such as files, printers, or applications on the other side of the VPN.
Inability to ping or access the VPN gateway: You may not be able to ping or access the VPN gateway on the other side of the VPN.
Inability to establish a VPN connection: You may not be able to establish a VPN connection between the two Fortigate routers.

Q: How do I troubleshoot issues with a Fortigate site-to-site VPN?

A: To troubleshoot issues with a Fortigate site-to-site VPN, you can follow these step-by-step guides:

Verify VPN tunnel status: Check the VPN tunnel status to ensure that it is up and running.
Verify firewall policies: Check the firewall policies to ensure that they are correctly configured to allow traffic to flow between the two networks.
Verify static routes: Check the static routes to ensure that they are correctly configured to route traffic between the two networks.
Verify VPN gateway configuration: Check the VPN gateway configuration to ensure that it is correctly configured to allow traffic to flow between the two networks.
Verify network configuration: Check the network configuration to ensure that it is correctly set up to allow traffic to flow between the two networks.

Q: What are some best practices for configuring a Fortigate site-to-site VPN?

A: Some best practices for configuring a Fortigate site-to-site VPN include:

Regularly monitor VPN tunnel status: Regularly monitor the VPN tunnel status to ensure that it is up and running.
Regularly check firewall policy logs: Regularly check firewall policy logs to ensure that there are no errors or issues that may be preventing traffic from flowing between the two networks.
Regularly check static route logs: Regularly check static route logs to ensure that there are no errors or issues that may be preventing traffic from being routed correctly between the two networks.
Regularly check VPN gateway logs: Regularly check VPN gateway logs to ensure that there are no errors or issues that may be preventing traffic from flowing between the two networks.
Regularly check network logs: Regularly check network logs to ensure that there are no errors or issues that may be preventing traffic from flowing between the two networks.

Q: Can I use a Fortigate site-to-site VPN to connect multiple offices or locations?

A: Yes, you can use a Fortigate site-to-site VPN to connect multiple offices or locations. This is commonly referred to as a "hub-and-spoke" configuration, where one office or location is the hub and the other offices or locations are the spokes.

Q: How do I secure a Fortigate site-to-site VPN?

A: To secure a Fortigate site-to-site VPN, you can use various security features such as:

Encryption: Use encryption to protect data in transit.
Authentication: Use authentication to ensure that only authorized users can access the VPN.
Access control: Use access control to restrict access to specific resources or networks.
Firewall policies: Use firewall policies to control traffic flow between the two networks.

Q: Can I use a Fortigate site-to-site VPN to connect to a cloud-based service?

A: Yes, you can use a Fortigate site-to-site VPN to connect to a cloud-based service. This is commonly referred to as a "cloud VPN" or "cloud-to-cloud VPN".

Q: How do I troubleshoot issues with a Fortigate site-to-site VPN in a cloud-based environment?

A: To troubleshoot issues with a Fortigate site-to-site VPN in a cloud-based environment, you can follow the same step-by-step guides as above, but with the added complexity of a cloud-based environment. You may also need to consult with your cloud provider's support team to resolve any issues related to the cloud-based environment.