Application-Based Routing in FortiGate

Application-Based Routing in FortiGate devices leverages the capabilities of Fortinet's FortiOS to intelligently direct traffic based on the specific applications being accessed. This feature is a part of Fortinet's broader suite of application-aware networking tools and is essential for optimizing network performance and ensuring that critical applications receive appropriate resources. Here’s a detailed explanation of Application-Based Routing in FortiGate:

Key Concepts of Application-Based Routing

1. Application Identification:

   • Deep Packet Inspection (DPI): FortiGate uses DPI to identify applications based on the traffic patterns and signatures within the packets. This allows the firewall to understand which application is generating the traffic, even if it’s using non-standard ports or protocols.
   • Application Control: FortiGate’s Application Control feature categorizes and manages application traffic based on pre-defined signatures and behavior.

2. Policy-Based Routing:

   • Routing Policies: Application-Based Routing allows the creation of policies that define how traffic from specific applications should be handled. These policies can dictate which WAN link or path should be used based on the application’s requirements.
   • Dynamic Path Selection: Traffic can be routed through different paths based on real-time performance metrics, ensuring optimal delivery for different applications.

3. Traffic Steering:

   • Quality of Service (QoS): Different applications might have varying QoS requirements. For example, video conferencing applications might require higher bandwidth and lower latency compared to standard web browsing. FortiGate can route traffic to meet these needs.
   • Load Balancing and Failover: Traffic from high-priority applications can be directed to dedicated links or paths, while less critical applications can use lower-cost links. Failover policies ensure that if a primary link fails, traffic can be rerouted through secondary links.

How to Configure Application-Based Routing in FortiGate

1. Define Application Rules:

   • Create Application-Based Policies: Configure policies that specify how different applications should be routed. This involves defining rules that match traffic based on application types, using FortiGate's Application Control database.
   • Set Conditions: Specify conditions such as source/destination addresses, application categories, and traffic volume to create precise routing rules.

2. Configure Routing Tables:

   • Static and Dynamic Routing: Depending on the traffic and application needs, configure static routes or use dynamic routing protocols to manage how traffic is forwarded.
   • Route Maps: Use route maps or policies to direct traffic based on the application-specific criteria set in your routing rules.

3. Apply Quality of Service (QoS) Settings:

   • Bandwidth Management: Set up QoS policies to allocate bandwidth based on application requirements, ensuring critical applications get the necessary resources.
   • Traffic Shaping: Configure traffic shaping rules to manage and prioritize application traffic, ensuring smooth performance.

4. Monitor and Adjust:

   • Traffic Analytics: Use FortiGate’s monitoring tools to track the performance and volume of application traffic. This helps in understanding how well the routing policies are performing and whether adjustments are needed.
   • Adjust Policies: Based on monitoring data, adjust the application-based routing policies to optimize performance and address any issues.

Benefits of Application-Based Routing

1. Improved Application Performance:

   • Prioritization: Ensures that high-priority applications receive the necessary bandwidth and performance levels, enhancing user experience and productivity.
   • Optimized Path: Routes traffic through the most efficient path, reducing latency and avoiding congestion for critical applications.

2. Enhanced Network Efficiency:

   • Cost Savings: Allows for more efficient use of network resources by directing less critical traffic through less expensive links.
   • Dynamic Adjustment: Automatically adjusts routing based on real-time conditions, improving overall network performance and reliability.

3. Granular Control:

   • Application-Specific Policies: Provides the ability to create detailed routing policies based on specific applications, offering fine-grained control over network traffic.

4. Increased Flexibility:

   • Adaptability: Easily adapts to changes in network conditions and application requirements, ensuring that routing policies remain effective over time.

Example Use Case

Consider an enterprise with multiple branches and a mix of critical applications like VoIP, video conferencing, and standard web browsing:

1. Policy Configuration:

   • VoIP Traffic: Create a policy that routes VoIP traffic through a high-bandwidth, low-latency link to ensure clear call quality.
   • Video Conferencing: Route video conferencing traffic through a dedicated link with guaranteed bandwidth to maintain high video quality.
   • Web Browsing: Direct web browsing traffic through a cost-effective broadband link, as it has lower priority compared to VoIP and video conferencing.

2. QoS and Monitoring:

   • Monitor Performance: Use FortiGate’s analytics tools to monitor the performance of each application and adjust policies as needed.
   • Adjust Routing: Based on performance data, adjust routing rules to optimize application delivery and network resource utilization.

In summary, Application-Based Routing in FortiGate provides a robust mechanism for managing and optimizing network traffic based on the specific needs of different applications. By leveraging FortiGate’s application identification and routing capabilities, organizations can ensure that critical applications receive the performance they require while optimizing the use of network resources.