Busque o RPM da sua plataforma no link : link (32 bits) e link (64 bits)
Instale: rpm -ivh mod_cloudflare-1.1.1-1.*
Edite o /etc/httpd/conf/httpd.conf
LoadModule cloudflare_module /usr/lib64/apache2/mod_cloudflare.so
<IfModule mod_cloudflare.c>
CloudFlareRemoteIPHeader CF-Connecting-IP
CloudFlareRemoteIPTrustedProxy 204.93.240.0/24 204.93.177.0/24 199.27.128.0/21 173.245.48.0/20 103.22.200.0/22 141.101.64.0/18 108.162.192.0/18
#DenyAllButCloudFlare
</IfModule>
Em 32 bits, altere lib64
para lib