MikroTik Certified Network Associate (MTCNA) Modules Practice Test

In NAT within MikroTik RouterOS, traffic is handled along two paths: when packets leave the router, their source address is translated, and when packets arrive with a destination that must be rewritten, the destination address is translated. These are implemented as two NAT chains: source NAT (src-nat) and destination NAT (dst-nat).

A typical use is to enable source NAT with masquerade so devices on a LAN can access the Internet using one public IP. Destination NAT is used for port forwarding, where an external IP:port is mapped to an internal device. The other terms listed belong to filtering or other actions, not the NAT chains.