CDN failover and redundancy are crucial for maintaining website uptime and performance. Failover switches traffic to a backup CDN during primary outages, while redundancy uses multiple CDNs to prevent single failure points. Common failure scenarios include network issues, server outages, DDoS attacks, and misconfigurations. Strategies like DNS-based failover, Anycast routing, and client-side JavaScript can provide quick alternatives. Multi-CDN setups, origin shields, and geo-redundant deployments help ensure global availability. Best practices include continuous monitoring, regular testing, optimized TTL settings, cloud-based load balancers, and integrated security. Implementing these techniques supports a resilient CDN that protects digital operations during disruptions.