Networking

A router is a device designed primarily to transmit packets based on IP address information. Its job is to receive a packet on one of its interfaces, look in the routing table and decide which interface and which next gateway to send the traffic to.

Almost every router has a basic security feature - the ability to create access rules - Access Control Lists (ACL). In them, you need to specify the source, destination IP addresses, protocol and port and mark whether such traffic is allowed or prohibited. In this way, you can regulate network traffic, limiting unwanted connections.

Example:

from host to host by protocol and port action Allow