Template:FAQ/Questions/a tcpip protocol that

Is there a TCP/IP protocol that runs on top of Bluetooth automatically?
There is a TCP/IP over bluetooth protocol service called PAN (or personal area network). PAN is provided on linux by the pand daemon, which is configured to run automatically in continuously-scanning client mode on the gumstix.

If the pand daemon sees a PAN master, it'll attempt to pair with it and establish a TCP/IP link, which shows up as the bnep0 interface on the gumstix.