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Applies to RouterOS: v6.29 +


IPv4 FastTrack handler is automatically used for marked connections. Use firewall action "fasttrack-connection" to mark connections for FastTrack. Currently only TCP and UDP connections can be actually FastTracked (even though any connection can be marked for FastTrack). IPv4 FastTrack handler supports NAT (SNAT, DNAT or both).

Note that not all packets in a connection can be FastTracked, so it is likely to see some packets going through slow path even though connection is marked for FastTrack. This is the reason why fasttrack-connection is usually followed by identical action=accept rule. FastTracked packets bypass firewall, connection tracking, simple queues, queue tree with parent=global, ip traffic-flow(restriction removed in 6.33), IP accounting, IPSec, hotspot universal client, VRF assignment, so it is up to administrator to make sure FastTrack does not interfere with other configuration;


IPv4 FastTrack is active if following conditions are met:

  • no mesh, metarouter interface configuration;
  • sniffer, torch and traffic generator is not running;
  • no active mac-ping, mac-telnet or mac-winbox sessions restriction removed in 6.33;
  • /tool mac-scan is not actively used;
  • /tool ip-scan is not actively used;
  • FastPath and Route cache is enabled under IP/Settings

Supported hardware

FastTrack is supported on the listed devices.

RouterBoard Interfaces
RB6xx series ether1,2
RB7xx series all ports
RB800 ether1,2
RB9xx series all ports
RB1000 all ports
RB1100, RB1000AHx2 ether1-11
RB1000AHx2 all ports
RB2011 series all ports
RB3011 series all ports
RB4011 series all ports
CRS series routers all ports except management interface (if the device has one)
CCR series routers all ports except management interface (if the device has one)
All devices wireless interfaces, if wireless-fp, wireless-cm2, wireless-rep or wireless (starting from 6.37) package used


Initial configuration

For example, in home routers with factory default configuration, you could FastTrack all LAN traffic with this one rule placed at the top of the Firewall Filter. The same configuration accept rule is required:

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

View of simple FastTrack rules in the firewall, it is important to have other filter or mangle rules to get the advantage of the FastTrack:

  • /ip firewall filter
Fasttrack1 example.png
  • /ip firewall mangle
Screenshot 2015-11-27 09.40.09.png

Warning: Queues (except Queue Trees parented to interfaces), firewall filter and mangle rules will not be applied for FastTracked traffic.

  • Connection is FastTracked until connection is closed, timed-out or router is rebooted.
  • Dummy rules will dissapear only after FastTrack firewall rules will be deleted/disabled and router rebooted.

FastTrack on RB2011

FastTrack is enabled on RB2011 at chain=forward with the rule from previous example. Bandwidth test with single TCP stream is sent,