Linux

Overview This document outlines the security policies and dynamic routing configurations for the network gateway, including firewall rules via nftables and BGP peering via BIRD. How Zones are Defined and Connected In this architecture, zones (zone_blue, zone_green, zone_red, and wan) directly correspond to network interfaces (either physical NICs, VLAN tags, or bridge interfaces) on the Gateway Server. Chain Structure (nftables): The firewall strictly controls traffic flow by matching the input interface (iif) and output interface (oif). For example, iif zone_blue oif zone_green tcp dport 22 accept explicitly states: If a packet enters the server via the zone_blue interface and is destined to leave via the zone_green interface on TCP Port 22, allow it. ...

Overview This document describes a method for simulating multiple servers belonging to different network domains on a single Linux host. Each simulated server runs inside its own Linux network namespace and is connected to a dedicated VLAN. Training and demonstration environments Each namespace behaves as an independent server with: Its own IP address Its own MAC address An SSH service A simple HTTP server Network Topology The Linux host uses the following interfaces: ...