NetProxy

Netproxy is a simple ipv6/ipv4 UDP & TCP proxy based on .NET 5.0. Tested on win10-x64 and ubuntu.16.20-x64.

Why?

We needed a simple, crossplatform IPV6 compatible UDP forwarder, and couldn't find a satisfying solution. Nginx was obviously a great candidate but building it on Windows with UDP forwarding enabled was quite a pain.

The objective is to be able to expose as an ipv6 endpoint a server located in an ipv4 only server provider.

Limitations

Each remote client is mapped to a port of the local server therefore:

• The original IP of the client is hidden to the server the packets are forwarded to.
• The number of concurrent clients is limited by the number of available ports in the server running the proxy.

Disclaimer

Error management exist, but is minimalist. IPV6 is not supported on the forwarding side.

Usage

• Compile for your platform following instructions at https://www.microsoft.com/net/core
• Rewrite the config.json file to fit your need
• Run NetProxy

Configuration

config.json contains a map of named forwarding rules, for instance :

{
 "http": {
 "localport": 80,
 "localip":"",
 "protocol": "tcp",
 "forwardIp": "xx.xx.xx.xx",
 "forwardPort": 80
 },
...
}

• localport : The local port the forwarder should listen to.
• localip : An optional local binding IP the forwarder should listen to. If empty or missing, it will listen to ANY_ADDRESS.
• protocol : The protocol to forward. tcp,udp, or any.
• forwardIp : The ip the traffic will be forwarded to.
• forwardPort : The port the traffic will be forwarded to.