V2Fly Website & Documentation

mKCP is a streaming transport protocol modified from the KCP protocol. It is designed to transfer any data stream in order using UDP as the base protocol.

Key characteristics:

• No Handshake: mKCP does not use a handshake procedure. Connections are determined by the unique identifier of the data stream found in received packets.
• Packetization: Data streams are split into small packets, each containing one or more segments.
• Segment Types: Communication consists of three segment types: Data, ACK (Acknowledge), and Ping.
• Versioning: mKCP has no version number; compatibility between different implementations is not guaranteed.

VMess is an original encrypted communication protocol developed by V2Ray. It is a stateless protocol based on TCP, meaning client and server do not require a handshake to transmit data; each transmission is independent of previous or subsequent ones.

VMess supports two authentication modes for the protocol header:

• AEAD Authentication: Uses AEAD encryption to ensure the integrity of the protocol header. This is the recommended method.
• MD5 Authentication: A legacy method using MD5 + AES-128-CFB. It cannot guarantee the integrity of the header itself. This method is deprecated.

Currently, VMess can automatically negotiate between AEAD and MD5 based on the protocol header.

V2Ray includes a built-in DNS server used for two purposes: matching routing rules based on resolved IPs and resolving target addresses for connections.

Important Considerations:

• Protocol Support: V2Ray only supports basic IP queries (A and AAAA records). For a full DNS experience, consider using a dedicated server like CoreDNS alongside V2Ray.
• Freedom Outbound Compatibility: For outbounds using the freedom protocol, the domainStrategy defaults to AsIs. This means DNS settings will not be applied to these outbounds unless you explicitly set domainStrategy to UseIP in your outbound configuration.

V2Ray includes several built-in services that supplement its core functionality. These services can be configured using the jsonv4 configuration format (available in V2Ray version 5.17.0 and later).

Available service modules include:

• Browser Forwarding Module: Handles browser-specific traffic forwarding.
• Policy Local Strategy: Manages local routing and access policies.
• Stats: Provides statistical information about the service.
• Background Observatory: Monitors background connections.
• Burst Observatory: Monitors concurrent/burst connections.
• Tun: Provides TUN device support for network tunneling.
• Subscription Manager: Manages user subscriptions.

V2Fly supports a wide range of proxy protocols for data encoding and traffic handling. These protocols can be categorized into transport/encryption protocols (like VMess, VLESS, Trojan, and Shadowsocks) and specialized routing/handling protocols (like DNS, Blockhole, and Freedom).

Supported protocols include:
* VMess
* VLESS
* VLite
* Trojan
* Shadowsocks
* Socks
* HTTP
* Freedom
* Dokodemo
* Blockhole
* DNS
* Loopback

The gdocsviewer transport protocol (available in v5.51.0+) is a streaming protocol that carries requests through the Google Docs Viewer. The client encodes requests as a series of HTTP requests, and the Google Docs Viewer acts as a proxy to execute them.

It is similar to the meek transport but uses Google Docs Viewer instead of a CDN for forwarding.

Warning: This is an experimental feature primarily generated by LLM and is not yet fully tested. Configuration formats and protocol details may change in future versions. It is generally slower than other methods and should only be used when other transport methods are unavailable.

Dokodemo-door (dokodemo-door) is an inbound protocol that listens on a local port and forwards all incoming data to a specified address and port on a target server. This effectively achieves port mapping.

Tip: For better performance when you want outbound connections to be re-routed by V2Ray, use it in conjunction with the Loopback protocol.

VLite is a protocol designed for packet acceleration, protection, stability, and forwarding. It is specifically optimized for UDP-based traffic and Peer-to-Peer (P2P) applications.

Note: VLite does not support TCP-based traffic forwarding.

VLite is a protocol designed for packet acceleration, protection, stabilization, and forwarding. It is specifically optimized for UDP-based traffic, with a primary focus on Peer-to-Peer (P2P) applications.

Important Limitations:

• It does not support TCP traffic proxying.
• To ensure only intended traffic uses VLite, it is recommended to use a router rule to direct only specific UDP packet address traffic to the VLite outbound.

"router": {
    "domainStrategy": "AsIs",
    "rule": [
      {
        "tag": "vlite",
        "domain": [
          {
            "type":"RootDomain",
            "value": "packet-addr.v2fly.arpa"
          }
        ]
      }
    ]
  }