FastTracked packets avoid the firewall, connection tracking, simple queues, the queue tree, among others, all connections processed by the router, it is like a bypass that is applied in order for connections to flow faster without being processed. .

The “FastTrack” functionality in MikroTik RouterOS is a feature designed to improve router performance by reducing the CPU load involved in processing packets. This is achieved by allowing certain traffic flows to be “throttled” or processed more efficiently, bypassing some of the more resource-intensive checks and features that would normally be applied to packets.

How does FastTrack work?

When FastTrack is enabled, RouterOS identifies traffic flows that can be accelerated based on rules defined in the firewall. Once a traffic flow is marked for FastTrack, subsequent packets from the same flow are processed more quickly, essentially “skipping” certain stages of the router's usual data path processing.

FastTrack Benefits

• Performance improvement: The main benefit is the significant reduction in router CPU load, allowing for higher throughput of network traffic, especially useful on links with high data rates.
• Capacity Increase: By reducing CPU load, FastTrack can help increase the amount of traffic the router can handle simultaneously, improving overall network capacity.

Considerations When Using FastTrack

• Compatibility with Other Features: Some advanced RouterOS features, such as deep packet filtering, packet inspection, QoS (Quality of Service), and VPN encryption, may be incompatible with FastTracked traffic. This means that traffic passing through FastTrack may not be processed by these features.
• Configuration and Security: It is important to carefully configure FastTrack rules to ensure that only the desired traffic is accelerated, maintaining network security and functionality.

Configuration Example

To enable FastTrack on RouterOS, a rule must be added to the firewall. A basic example for FastTrack of common Internet traffic would be:

/ip firewall filter 
add action=fasttrack-connection chain=forward connection-state=established,related

This command creates a rule that marks established and related connections for FastTrack, throttling traffic that meets these conditions.

In short, FastTrack is a powerful tool within RouterOS to improve network traffic performance. However, it should be used with an understanding of its impacts on the network and in combination with appropriate security configuration.