This page was last updated in January 2016 and is accurate for router version 0.9.24.


I2PTunnel is a tool for interfacing with and providing services on I2P. Destination of an I2PTunnel can be defined using a hostname, Base32, or a full 516-byte destination key. An established I2PTunnel will be available on your client machine as localhost:port. If you wish to provide a service on I2P network, you simply create I2PTunnel to the appropriate ip_address:port. A corresponding 516-byte destination key will be generated for the service and it will become avaliable throughout I2P. A web interface for I2PTunnel management is avaliable on localhost:7657/i2ptunnel/.

Default Services


  • I2P Webserver - A tunnel pointed to a Jetty webserver run on localhost:7658 for convenient and quick hosting on I2P.
    The document root is:
    Unix - $HOME/.i2p/eepsite/docroot
    Windows - %LOCALAPPDATA%\I2P\I2P Site\docroot, which expands to: C:\Users\**username**\AppData\Local\I2P\I2P Site\docroot


  • I2P HTTP Proxy - localhost:4444 - A HTTP proxy used for browsing I2P and the regular internet anonymously through I2P. Browsing internet through I2P uses a random proxy specified by the "Outproxies:" option.
  • Irc2P - localhost:6668 - An IRC tunnel to the default anonymous IRC network, Irc2P.
  • mtn.i2p2.i2p - localhost:8998 - The anonymous monotone sourcecode repository for I2P
  • smtp.postman.i2p - localhost:7659 - A SMTP service provided by postman at
  • pop3.postman.i2p - localhost:7660 - The accompanying POP sevice of postman at


I2PTunnel Configuration

Client Modes


Opens a local TCP port that connects to a service (like HTTP, FTP or SMTP) on a destination inside of I2P. The tunnel is directed to a random host from the comma seperated (", ") list of destinations.


A HTTP-client tunnel. The tunnel connects to the destination specified by the URL in a HTTP request. Supports proxying onto internet if an outproxy is provided. Strips HTTP connections of the following headers:

  • Accept, Accept-Charset, Accept-Language and Accept-Ranges as they vary greatly between browsers and can be used as an identifier.
  • Referer:
  • Via:
  • From:

The i2ptunnel compression is requested with the HTTP header:

  • X-Accept-Encoding: x-i2p-gzip;q=1.0, identity;q=0.5, deflate;q=0, gzip;q=0, *;q=0

The response indicating i2ptunnel compression contains the following HTTP header:

  • Content-Encoding: x-i2p-gzip

Depending on if the tunnel is using an outproxy or not it will append the following User-Agent:

  • Outproxy: User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: Gecko/20100625 Firefox/3.6.6
  • Internal I2P use: User-Agent: MYOB/6.66 (AN/ON)

IRC Client

Creates a connection to a random IRC server specified by the comma seprated (", ") list of destinations. Only a whitelisted subset of IRC commands are allowed due to anonymity concerns. The following whitelist is for commands inbound from the IRC server to the IRC client.

  • CAP
  • H
  • JOIN
  • KICK
  • MODE
  • NICK
  • PART
  • PING
  • QUIT

There is also a whitelist is for commands outbound from the IRC client to the IRC server. It is quite large due to the number of IRC administrative commands. See the source for details. The outbound filter also modifies the following commands to strip identifying information:

  • PART
  • PING
  • QUIT
  • USER

SOCKS 4/4a/5

Enables using the I2P router as a SOCKS proxy.


Enables using the I2P router as a SOCKS proxy with the command whitelist specified by IRC client mode.


Creates a HTTP tunnel and uses the HTTP request method "CONNECT" to build a TCP tunnel that usually is used for SSL and HTTPS.


Creates a UDP-server attached to a Streamr client I2PTunnel. The streamr client tunnel will subscribe to a streamr server tunnel.

Server Modes


Creates a destination to a local ip:port with an open TCP port.


Creates a destination to a local HTTP server ip:port. Supports gzip for requests with Accept-encoding: x-i2p-gzip, replies with Content-encoding: x-i2p-gzip in such a request.

HTTP Bidirectional

Functions as both a I2PTunnel HTTP Server, and a I2PTunnel HTTP client with no outproxying capabilities. An example application would be a web application that does client-type requests, or loopback-testing an I2P Site as a diagnostic tool.

IRC Server

Creates a destination that filters the reqistration sequence of a client and passes the clients destination key as a hostname to the IRC-server.


A UDP-client that connects to a media server is created. The UDP-Client is coupled with a Streamr server I2PTunnel.