09 - Network Security

Hardening Standards & Guidance

CIS Benchmarks: Industry-standard configuration guides (hundreds of OS/app checklists); consensus-based, prescriptive hardening steps
STIGs (Security Technical Implementation Guides): DoD-specific hardening requirements (DISA); more rigid/strict than CIS; mandatory for federal systems
Vendor Guidance: Manufacturer hardening guides (Cisco Hardening Guide, Microsoft Security Baselines); addresses product-specific features and known vulnerabilities

Wireless Security

WAP Placement: Site Surveys (measure coverage/interference); Heat Maps (visualize signal strength and overlap); minimize bleed to parking lots/adjacent buildings
Encryption Evolution:
WEP: Broken (RC4 stream cipher); never use
WPS (Wi-Fi Protected Setup): PIN method vulnerable to brute force ( Pixie Dust attack); disable button/PIN, use only if necessary
WPA2: PSK (Pre-Shared Key, home/SMB) vs Enterprise (802.1X/RADIUS); AES-CCMP encryption; vulnerable to KRACK
WPA3: SAE (Simultaneous Authentication of Equals) replaces PSK; forward secrecy; Enhanced Open (OWE - Opportunistic Wireless Encryption) encrypts open networks without passwords
DPP (Device Provisioning Protocol / Wi-Fi Easy Connect): Replaces WPS; uses QR codes or NFC for secure onboarding without PIN vulnerabilities

Automation & Validation

Config Management: Ansible (agentless, YAML playbooks), Puppet, Chef; enforce desired state automatically, prevent configuration drift
SCAP (Security Content Automation Protocol): Automated verification against hardening standards; XCCDF (checklist format), OVAL (vulnerability definitions), SCC (scanner tool for STIGs)
Baseline Practices: Change default passwords/Community strings (SNMP); disable unnecessary services/ports (reduces attack surface); remove default accounts (guest, admin)

Network Access Control (NAC)

Agent-Based: Persistent software on endpoint; deep inspection (AV status, patch level) but deployment/maintenance overhead; Dissolvable Agent: Runs temporarily then removes itself (flexible, less intrusive)
Agentless: Uses SNMP, WMI, or Active Directory GPOs to assess posture; easier deployment but limited visibility (can’t check local security settings deeply); MAC Authentication Bypass (MAB) as fallback

Web Filtering

Categories: Block/allow by URL classification (malware, gambling, social media); SSL Inspection (MITM decryption to inspect HTTPS traffic, privacy concerns)
Deployment: Cloud-based (DNS filtering, off-network protection) vs On-premise (proxy appliance); Time-based policies (allow social media only at lunch)