CDN Cheat Sheet 2026
The 30 highest-yield CDN facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.
- A CDN pull zone is configured with a 1-hour TTL. The origin content is updated. What must the operator do to immediately serve fresh content? → Issue a cache purge/invalidation for the affected URLs
- What is the benefit of root cause analysis? → Prevent recurrence
- What is a common cause of CDN performance issues? → Overload or congestion
- What is a 'positive security model' WAF approach? → Allowing only explicitly defined legitimate request patterns and blocking everything else
- How does SSL/TLS enhance CDN security? → Encrypt data transmission
- Why is latency monitoring important? → Maintain fast delivery
- Which of the following best describes a key competency required for cost optimization & traffic management in CDN practice? → Strong analytical skills combined with effective communication and ethical judgment
- A CDN WAF is configured in 'monitor' mode. What is the effect on malicious traffic? → Traffic is allowed but logged for analysis
- What is a cache miss? → Content not found in cache
- What is 'token escalation' in the context of CDN security? → An attack where a low-privilege token is manipulated to gain access to restricted content
- Which of the following best describes a key competency required for video streaming & media delivery in CDN practice? → Strong analytical skills combined with effective communication and ethical judgment
- In CDN geo-restriction, which mechanism does the CDN use to determine a user's geographic location? → IP-to-geolocation database mapping the client's IP address to a country
- What is the primary purpose of a Web Application Firewall (WAF) deployed at the CDN edge? → To inspect and filter HTTP/HTTPS traffic against application-layer attacks
- What is caching in a CDN? → Storing content near users
- Why is monitoring important for CDN performance? → Detect and optimize delivery
- In the context of CDN certification, what is the most important consideration when implementing ssl/tls & certificate management? → Ensuring alignment with established standards, stakeholder needs, and best practices
- What is the benefit of geographic load balancing? → Reduce latency by location
- A signed CDN URL contains the parameter `exp=1719878400`. What does this value represent? → The Unix timestamp after which the token is no longer valid
- Which CDN feature allows operators to set different cache TTLs at the origin shield layer versus the edge PoP layer? → Surrogate-Control header or CDN-specific cache directives
- Hotlink protection in a CDN primarily works by checking which HTTP header on incoming requests? → Referer
- What is a cache hit? → Content served from cache
- What is a Distributed Denial of Service (DDoS) attack? → Flooding server with traffic
- What is the main purpose of content distribution in a CDN? → Deliver content from nearby servers
- Mutual TLS (mTLS) at the CDN edge is most appropriate for which use case? → Securing machine-to-machine API communication between known services and the CDN edge
- Which of the following best describes a key competency required for api gateway & rate limiting in CDN practice? → Strong analytical skills combined with effective communication and ethical judgment
- Which hashing algorithm is most commonly used to generate HMAC-based secure tokens in CDN implementations? → SHA-256
- What is the role of web application firewalls (WAF) in CDN? → Filter malicious traffic
- Why is scalability important in CDN architecture? → Handle growing traffic efficiently
- What is a common CDN security feature? → DDoS protection and SSL
- What is the primary purpose of an origin shield in a CDN architecture? → To act as a mid-tier cache that reduces the number of requests reaching the origin server
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