Mastering VLAN and Inter-VLAN Routing on Fortigate Firewall

Table of Contents

1. Introduction
2. Configuring VLAN on the Firewall
   1. Logging in to the Firewall
   2. Configuring VLAN on the LAN Interface
   3. Creating a VLAN Interface
   4. Configuring DHCP on the VLAN Interface
3. Creating Firewall Policies for VLAN Communication
   1. Allowing Internet Access for VLAN
   2. Allowing Communication from LAN to VLAN
   3. Allowing Communication from VLAN to LAN
   4. Implicit Deny Rule
4. Conclusion

📗 Configuring VLAN and Inter VLAN Routing on a 48 Firewall

In this article, I will guide you through the process of configuring VLAN (Virtual Local Area Network) and inter-VLAN routing on a 48 firewall. VLANs allow you to segment your network into virtual LANs, while inter-VLAN routing enables communication between these VLANs.

Introduction

Before we dive into the technical details, let me first introduce the concept of VLANs and inter-VLAN routing. VLAN is a technology that enables the creation of isolated virtual networks within a physical network infrastructure. This segregation allows for improved security, better network management, and more efficient use of network resources. Inter-VLAN routing, on the other hand, is the process of forwarding traffic between VLANs, enabling communication between different virtual networks.

Configuring VLAN on the Firewall

Logging in to the Firewall

To begin the configuration process, you need to log in to your firewall. Make sure you have the necessary credentials to access the firewall's administration interface.

Configuring VLAN on the LAN Interface

One of the common methods for configuring VLAN is by using subinterfaces on the LAN port. Start by accessing the LAN port configuration and remove the existing IP address assigned to the physical interface. This can be done by selecting the LAN port, double-clicking on it, and removing the IP address.

Creating a VLAN Interface

To create a VLAN, you need to create a new interface with the VLAN type. Give the VLAN a name and specify the VLAN ID. Choose the LAN port as the interface type and assign the IP address that was previously removed from the physical interface to the VLAN interface. Ensure that the VLAN interface is properly configured with the necessary settings like enabling ping, HTTPS access, and SSH access. Additionally, you can configure DHCP settings for the VLAN if required.

Configuring DHCP on the VLAN Interface

If you want to assign IP addresses dynamically to the devices connected to the VLAN, you can configure a DHCP server on the VLAN interface. Specify the IP address range for the DHCP server and enable other settings like DNS configuration, lease time, and firewall policies.

Creating Firewall Policies for VLAN Communication

To allow communication between VLANs and control the traffic flow, you need to configure firewall policies. These policies define the rules for traffic forwarding and filtering.

Allowing Internet Access for VLAN

Create a firewall policy that allows VLAN traffic to access the internet. Specify the source as the VLAN network, the destination as the internet, and select the necessary services like HTTP, HTTPS, and DNS. You can also enable security features like antivirus scanning, web filtering, and application control.

Allowing Communication from LAN to VLAN

If you want devices in the LAN network to communicate with devices in the VLAN, create a firewall policy that allows the traffic from the LAN network to the VLAN. Define the source as the LAN network and the destination as the VLAN network. Leave the services open to allow all traffic or specify the required services. Enable any necessary security features and ensure the policy is enabled.

Allowing Communication from VLAN to LAN

Similarly, create a firewall policy to allow traffic from the VLAN network to the LAN network. This policy enables devices in the VLAN to communicate with devices in the LAN. Set the source as the VLAN network and the destination as the LAN network. Configure the necessary services and security features, and enable the policy.

Implicit Deny Rule

To ensure unauthorized traffic is blocked, create an implicit deny rule as the last firewall policy. This rule will deny any traffic that does not match the previous policies. By having this rule in place, you can have better control over the allowed traffic flow.

Conclusion

Configuring VLANs and inter-VLAN routing on a 48 firewall can provide you with a more secure and efficient network infrastructure. By properly configuring VLANs and firewall policies, you can isolate network segments, control traffic flow, and ensure better network management. Remember to consider your specific network requirements and security needs when implementing VLANs and inter-VLAN routing.

Highlights

• VLAN (Virtual Local Area Network) allows for network segmentation and improved security.
• Inter-VLAN routing enables communication between different VLANs.
• Configuring VLAN on a firewall involves creating VLAN interfaces on the LAN port.
• Firewall policies control traffic flow between VLANs and define access rules.
• Creating an implicit deny rule prevents unauthorized traffic from accessing the network.