FRP & STCP Tunnels

FRP (Fast Reverse Proxy) is a high-performance reverse proxy that can expose internal TCP and UDP services behind NAT or firewalls to the outside world.

STCP (Secret TCP) Pattern

While standard FRP proxies open a public port on the VPS (frps), the STCP (Secret TCP) mode keeps traffic private and encrypted:

[ Homelab Service ] <--- [ frpc (Server) ]
                                | (Encrypted STCP Tunnel)
                         [ frps (Public VPS) ]
                                |
[ Client Machine ]  <--- [ frpc (Visitor) ]

Key Advantages

  1. No Open Public Ports: The public VPS relay does not bind listening ports for the service. Traffic cannot be scanned or accessed by arbitrary internet clients.
  2. Mutual Secret Authentication: Only authorized clients running a matching visitor configuration with the shared secret key can establish a local socket connection to the target service.
  3. P2P Acceleration: FRP can negotiate peer-to-peer connections between client and server when possible, falling back to relaying through the VPS.