Cloudflare provides edge-level protection for your websites. Integrating IP threat intelligence with Cloudflare rules adds another layer of defense.
Cloudflare IP Blocking Options
Cloudflare offers several methods to block malicious IPs: IP Access Rules, Firewall Rules, and the newer WAF Custom Rules.
Blocking at the Cloudflare edge means malicious requests never reach your origin servers.
Integration Methods
IP Access Rules
Simple allow/block rules applied at the account or zone level. Easy to manage but limited to 50,000 rules.
Firewall Rules (deprecated)
More complex logic with IP lists. Being replaced by WAF Custom Rules.
WAF Custom Rules
Modern replacement using IP Lists for efficient management of large blocklists.
Automating via API
Use the Cloudflare API to programmatically manage IP blocks:
API example - Block an IP:
curl -X POST "https://api.cloudflare.com/client/v4/zones/{zone_id}/firewall/access_rules/rules" \
-H "Authorization: Bearer {token}" \
-d '{"mode":"block","configuration":{"target":"ip","value":"1.2.3.4"}}'
Best Practices
- Use IP Lists - Group related IPs into lists for easier management
- Set Appropriate Actions - Use "Challenge" for suspicious IPs, "Block" for confirmed threats
- Monitor Analytics - Review Cloudflare security analytics for blocked requests and patterns
Integrate with Cloudflare
Use our API to automate Cloudflare IP block updates.