Beyond individual IPs, Cloudflare examines the autonomous system number (ASN)—the broader network the IP belongs to. Datacenter ASNs are automatically flagged; ISP ASNs (Comcast, AT&T, Deutsche Telekom) pass this check.
Replace default ISP DNS settings with trusted public options like Google DNS (8.8.8.8) or Cloudflare's own 1.1.1.1. Advanced Scripting and Scraper Fixes unblock challenges cloudflare repack