Introduction to frp
frp, short for "fast reverse proxy," is an innovative open source tool designed to help expose local servers behind a NAT or firewall to the Internet. This makes frp an essential utility for users who need seamless access to internal resources from external networks without the usual connectivity hurdles.
What is frp?
At its core, frp is designed to facilitate the communication across network boundaries, supporting TCP and UDP protocols, alongside HTTP and HTTPS. It's a versatile solution that can forward requests to internal services via domain names and even offers a Peer-to-Peer (P2P) connect mode to further enhance data transmission capabilities.
How Does frp Work?
The operational magic of frp revolves around its ability to establish connections between a public server and a local network server. Here’s how it typically works: a public-facing server (referred to as frps) connects with an internal client (frpc), allowing external devices to access services running on the client machine as if they were directly connected.
Example Usage:
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Access Your Computer via SSH: You can reach your computer in a LAN securely over SSH, enabling remote work or server management without being physically present.
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Multiple SSH Services on a Single Port: frp can conveniently manage multiple SSH services, letting them share the same port—ideal for complex environments where ports are at a premium.
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Access Internal Web Services: If you host a web service in a LAN, frp allows for exposure over a custom domain for easy, external testing and access.
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Forward DNS Queries: With frp, redirecting DNS requests to public DNS servers, such as Google's, becomes straightforward and efficient.
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Expose Unix Domain Sockets: By translating Unix domain sockets to TCP, frp makes it possible to interact with internal services like Docker from outside the local network.
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Enable HTTPS on Local Sites: It also covers security by facilitating HTTPS connections even if the local service only runs HTTP natively.
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Private Service Exposure: Using secret TCP (stcp) mode, frp ensures that only authorized clients with a shared key can access sensitive services.
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P2P Mode: For large data transfers directly between clients, frp's P2P (xtcp) mode optimizes efficiency and speed.
Development and Features
frp is actively developed with numerous features that cater to a broad range of use cases. These include support for multiple configuration formats, environment variable configurations, and extensive authentication methods such as token and OIDC authentication.
One standout feature is its robust system for managing and monitoring—offering server dashboards, client admin UIs, and integration with monitoring tools like Prometheus.
Development Roadmap
The project is currently evolving towards version 2, focusing on modernizing and expanding its capabilities. However, this version will not maintain compatibility with version 1 due to significant architectural improvements inspired by cloud-native trends and service mesh strategies.
Support and Contribution
As an open-source initiative, frp thrives on community support and contributions. The project accepts donations via GitHub Sponsors and PayPal, ensuring that it remains accessible and continuously improved for all users.
By addressing everyday connectivity challenges creatively and reliably, frp continues to be a vital tool for developers, IT professionals, and network administrators worldwide.