คำตอบ: CPU (Central Processing Unit) / Processor
CPU ไม่ใช่ Network Security Device เพราะ CPU เป็น Hardware ประมวลผลกลาง (Processor) ของคอมพิวเตอร์/เซิร์ฟเวอร์ ใช้รัน Instruction Set ไม่ได้ทำหน้าที่ควบคุม/กรอง/ตรวจสอบ Traffic เครือข่าย
Network Security Devices (อุปกรณ์ความปลอดภัยเครือข่าย) คืออะไร?
อุปกรณ์ (Hardware/Appliance) หรือ Software ที่ออกแบบมาเฉพาะเพื่อ ป้องกัน, ตรวจจับ, ตอบสนอง ภัยคุกคามบนเครือข่าย
ประเภท Network Security Devices หลัก
| Category | Devices / Solutions | Function |
|---|---|---|
| Firewall | Next-Gen Firewall (NGFW) | App-ID, User-ID, IPS, AV, SSL Decrypt, DNS Security (Palo Alto, Fortinet, Check Point, Cisco) |
| Web Application Firewall (WAF) | Layer 7 Protection: OWASP Top 10, Bot, API Security (Cloudflare, AWS WAF, F5, Imperva) | |
| Database Firewall | SQL Injection Protection, Virtual Patching (Imperva, Oracle Audit Vault) | |
| Intrusion Detection/Prevention | Network IDS/IPS (NIDS/NIPS) | Signature + Anomaly Detection, Inline/SPAN (Snort, Suricata, Cisco FirePOWER) |
| Host IDS/IPS (HIDS/HIPS) | Agent บน Host: File Integrity, Rootkit Detection (OSSEC, Wazuh, CrowdStrike) | |
| Wireless IPS (WIPS) | Rogue AP, Evil Twin, Wireless Attack Detection | |
| Access Control | Network Access Control (NAC) | 802.1X, MAB, Posture, Guest/Contractor (Cisco ISE, Aruba ClearPass, FortiNAC) |
| Zero Trust Network Access (ZTNA) | Identity-based, Device Trust, Micro-segmentation (Zscaler, Cloudflare, Twingate) | |
| VPN Gateway / SSL VPN | Remote Access, Site-to-Site (Palo Alto, Fortinet, Cisco, OpenVPN, WireGuard) | |
| Content & Threat | Secure Web Gateway (SWG) | URL Filtering, Malware Scan, DLP, CASB (Zscaler, Netskope, Forcepoint) |
| Email Security Gateway | Anti-Spam, Anti-Phishing, Sandbox, DMARC (Proofpoint, Mimecast, Cisco ESA) | |
| DNS Security / Protective DNS | Block Malicious Domains, DGA, C2 (Cisco Umbrella, Quad9, Infoblox) | |
| Monitoring & Analysis | SIEM | Log Collection, Correlation, Alerting (Splunk, Sentinel, Elastic, QRadar) |
| Network Detection & Response (NDR) | Traffic Analysis, Encrypted Traffic Analysis, Threat Hunting (Corelight, Vectra, Darktrace) | |
| Packet Capture / Forensics | Full PCAP, Indexing (Endace, NetWitness, Arkime) | |
| DDoS Protection | On-prem DDoS Appliance | Volumetric/Protocol/App Layer Mitigation (Arbor, Radware, FortiDDoS) |
| Cloud DDoS (Always-on / On-demand) | AWS Shield, Cloudflare, Akamai, Azure DDoS |
อุปกรณ์เครือข่ายทั่วไป (Network Infrastructure) ≠ Security Devices
| Device | Primary Function | Security Role |
|---|---|---|
| Router | Routing (Layer 3), Forwarding | ACL, uRPF, BGP Security (Secondary) |
| Switch | Switching (Layer 2), VLAN | Port Security, DHCP Snooping, DAI, 802.1X (Secondary) |
| Load Balancer | Traffic Distribution (L4/L7) | WAF Module, DDoS, SSL Offload (Secondary) |
| Proxy Server | Forward/Reverse Proxy, Caching | Content Filtering, DLP, SSL Inspect (Secondary) |
| Wireless Controller / AP | Wi-Fi Management, RF | WPA3, NAC, WIPS (Secondary) |
ตัวอย่างคำถามสอบ / Certification Style
Question: Which of the following is NOT a network security device?
A) Firewall
B) IDS/IPS
C) Router
D) CPUAnswer: D) CPU
Reason: CPU is a compute component, not a network security appliance. Router (C) has security features (ACL, uRPF) but primarily infrastructure.
5 Types of Security (Security Domains)
- Critical Infrastructure Security: SCADA/ICS/OT, Power, Water, Transport
- Network Security: Firewall, IDS/IPS, NAC, Segmentation, VPN
- Cloud Security: CSPM, CWPP, CIEM, CNAPP, SASE
- IoT/OT Security: Device Auth, Firmware, Network Segregation, IEC 62443
- Application Security: SAST, DAST, SCA, Container Sec, API Sec, DevSecOps
Network Security Equipment (อุปกรณ์เครือข่ายเพื่อความปลอดภัย)
หมายถึง Hardware Appliances / Virtual Appliances ที่ Deploy เพื่อ:
• Monitor (Visibility)
• Prevent (Block/Filter)
• Detect (Alert/Analyze)
• Respond (Automated/Manual)
ปกป้อง Digital Assets: Network Traffic, Infrastructure, Data, Applications
