That means that the 1 st rule that is matched, then the other rules will not be checked. Those filter rules are processed in order (in sequence). You can create many filter rules in the MikroTik firewall.

So now you know when you want to configure some filter rules, you have an idea which chain should you use based on your scenario. For example, if you do ping from the MikroTik router itself to, that’s fall into the chain output. Chain Output: This belongs to the traffic sourced from the MikroTik router and going to somewhere else.Same if you do SSH to the router, or ping to the router. Think for example when you open Winbox session to the MikroTik router, that’s chain input because the traffic is going to the router itself. Chain Input: This means the traffic that is destinated and terminated to the MikroTik router itself.For example, if you have a PC in the LAN and you want to go to on your browser, then the traffic is sourced from your PC, going via the router to server on the internet. Chain Forward: This means that the traffic that is traversing the MikroTik router and going to somewhere else.Those can be seen when you create a new filter rule on the firewall as the following: You have 3 chains in the Firewall of MikroTik RouterOS as the following: The chain is used in the firewall so the RouterOS can see on which way does he want to restrict the packets. When speaking about Firewall in MikroTik, you always have what is called as chain. RAW: drop or bypass packets before reaching the connection tracking.Mangle: to mark connections and/or packets.NAT: SRCNAT and DSTNAT to translate source and destination addresses.For instance, you can use the MikroTik RouterOS firewall to do the following:

Those firewall functions are applied on the MikroTik RouterOS.

Classify and mark connections and packets for QOS or Routing policy.

Generally, there are 3 main functions for the firewall: MikroTik RouterOS has a very nice firewall capability making the router to become a firewall appliance.

Mikrotik transparent firewall