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Cloudflare IP Whitelisting

March 26, 2021 — ~meskin

Here’s how I block all non Cloudflare IPs from accessing my server.

Whitelist all Cloudflare IPs with IPtables

IPv4

iptables -I INPUT -p tcp -m multiport --dports http,https -s 173.245.48.0/20 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 103.21.244.0/22 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 103.22.200.0/22 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 103.31.4.0/22 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 141.101.64.0/18 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 108.162.192.0/18 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 190.93.240.0/20 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 188.114.96.0/20 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 197.234.240.0/22 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 198.41.128.0/17 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 162.158.0.0/15 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 104.16.0.0/12 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 172.64.0.0/13 -j ACCEPT iptables -I INPUT -p tcp -m multiport --dports http,https -s 131.0.72.0/22 -j ACCEPT

IPv6

ip6tables -I INPUT -p tcp -m multiport --dports http,https -s 2400:cb00::/32 -j ACCEPT ip6tables -I INPUT -p tcp -m multiport --dports http,https -s 2606:4700::/32 -j ACCEPT ip6tables -I INPUT -p tcp -m multiport --dports http,https -s 2803:f800::/32 -j ACCEPT ip6tables -I INPUT -p tcp -m multiport --dports http,https -s 2405:b500::/32 -j ACCEPT ip6tables -I INPUT -p tcp -m multiport --dports http,https -s 2405:8100::/32 -j ACCEPT ip6tables -I INPUT -p tcp -m multiport --dports http,https -s 2a06:98c0::/29 -j ACCEPT ip6tables -I INPUT -p tcp -m multiport --dports http,https -s 2c0f:f248::/32 -j ACCEPT

Block all non-cloudflare IPs

IPv4

iptables -A INPUT -p tcp --dport http,https -j DROP

IPv6

ip6tables -A INPUT -p tcp --dport http,https -j DROP

Last updated on Friday, 26 Mar, 2021.

tags: IT