BackgroundNetwork Auditing EssentialsProtocolsOSI ModelRouters and SwitchesFirewallsAuditing Switches, Routers, and FirewallsGeneral Network Equipment Audit StepsAdditional Switch Controls: Layer 2Additional Router Controls: Layer 3Additional Firewall ControlsTools and TechnologyKnowledge BaseMaster ChecklistsGeneral Network Equipment Audit StepsAuditing Layer 2 Devices: Additional Controls for SwitchesAuditing Layer 3 Devices: Additional Controls for RoutersAuditing Firewalls: Additional Controls