Yes you can, but is not apache who handles traffic filtering, you need a firewall or something like iptables.

here is the list of Cloudflares IP addresses: https://www.cloudflare.com/ips

There are plenty iptables tutorials online,

Hi

Thanks for your response!

I have added following rule in UFW:

ufw allow proto tcp from <cloudflare_ips> to any 80

Do you think this step could help curtail attacks on the server as the requests gets filtered through CF and other direct traffic gets blocked.

PS: I have only open ports 80 & 443. All other ports are blocked.