Efficient Routing and Firewall Management with MikroTik Routers

Efficiency in routing and firewall management is paramount in a network environment, especially when tasked with handling substantial traffic volumes. This document elucidates best practices for configuring MikroTik routers to realize optimal performance, concentrating on FastTrack technology and judicious firewall rule arrangement.

FastTrack Configuration

MikroTik routers offer FastTrack, a performance optimization feature that enables specific packets to bypass various handling layers. The benefit of this bypass is twofold: reduced CPU load and increased throughput.

The Advantage of FastTrack

FastTrack substantially lightens the burden on the router's CPU, thereby accommodating more connections and amplifying throughput. This efficiency is particularly invaluable for Peer-to-Peer (P2P) connections, such as those utilized by Polkadot nodes.

Implementing FastTrack

FastTrack can be implemented with precision to enhance the performance of Polkadot P2P ports.

  1. Identify the Connections: Ascertain the connections you desire to FastTrack. Typically, for Polkadot nodes, the FastTrack would be applied to the P2P ports (e.g., 30333) responsible for inter-node communication.

  2. Construct the FastTrack Rule: Position the FastTrack rule at the zenith of the firewall filter rules. The following example demonstrates a FastTrack rule for Polkadot P2P port 30333, targeting the IP address

    /ip firewall filter add chain=forward action=fasttrack-connection dst-address= protocol=tcp dst-port=30333 connection-state=established,related
  3. Formulate a Corresponding Accept Rule: FastTracking a connection does not automatically validate it, necessitating a corresponding 'accept' rule subsequent to the FastTrack rule:

    /ip firewall filter add chain=forward action=accept dst-address= protocol=tcp dst-port=30333 connection-state=established,related
  4. Configure Port Forwarding: Accurate port forwarding is fundamental for channeling traffic to the Polkadot node. An example of a Destination NAT rule for directing traffic on port 30333 to the internal address is as follows:

    /ip firewall nat add chain=dstnat action=dst-nat to-addresses= to-ports=30333 protocol=tcp dst-address= dst-port=30333

Ordering Firewall Rules

The sequencing of firewall rules is pivotal, as rules are processed linearly. The advised general order is:

  1. Essential Drop Rules: Intercept known malicious IPs or undesired traffic.
  2. FastTrack Rules: As detailed above.
  3. General Allow and Deny Rules: These encompass standard protocols and services either to be permitted or obstructed.

Monitoring and Refinement

MikroTik offers diverse tools to observe your router's performance:

  • Resource Monitoring: Utilize /system resource print to inspect CPU and memory usage.
  • Connection Tracking: Examine FastTrack connections with /ip firewall connection tracking print.

Consistent monitoring is instrumental in detecting performance restrictions and avenues for further enhancement.