Web pages use ports 80,443
Cloudflare can proxy almost all TCP ports. Supports two kinds of agents:
Application Level (Layer 7) HTTP Agent, Spectrum, Transport Level (Layer 4) TCP Agent
Cloudflare can proxy traffic through HTTP / HTTPS ports listed below.
If your traffic is on a different port, you can add it as something we do not proxy to the record in the Cloudflare DNS area file (grey cloud = no Cloudflare proxy or record cache).
The HTTP ports supported by Cloudflare are:
The HTTPs ports supported by Cloudflare are:
For Pro plans and later versions, you can use WAF Rule ID 100015 to block traffic on ports other than 80 and 443: "Prevent requests on all ports except 80 and 443".
Ports 80 and 443 are the only ports:
For HTTP/HTTPS traffic in China within the region with Chinese network enabled
Proxy for Cloudflare applications
When CloudFlare's cache is available
Of course, if you have money, you can customize ports, basically all TCP ports can be.