The traffic that is routed through I2P is organized in tunnels and in tunnel pools. Every tunnel pool – or simply called tunnel – has it’s own destination (~I2P-IP). You can configure wich tunnels are open at http://localhost:7657/i2ptunnel/index.jsp. When you are very new to I2P there is no need to change anything here, but when you become more familar with I2P, you see the advantages of that.
The easiest sort of applications that run with I2P are client/server applications. You only have to configure that it should use a proxy or that it should connect to a certain port.
Applications like Bittorrent and many other p2p-programs must be adjusted to work together with I2P. I2P has two interfaces to communicate with those services: BOB and SAM
Services that are commonly run together with I2P:
Special adjusted software: