2 Beaglebones connected using I2C

I’m trying to connect 2 Beaglebones type black using I2C, one board as master and another one as slave. I’ve tried to use the i2c-1 and i2c-2, but always when I try, I don’t get some address if I use “i2cdetect -r 1” (or 2). For your known, I’m connecting only SDA and SCL pins, it means, I’m not connecting 3,3V and GND pins. Can someone give me some advice?
Thanks in advanced.

It seems it was not possible till a few days ago

http://events.linuxfoundation.org/sites/events/files/slides/ELCE15-WolframSang-ShinyNewI2CSlaveFramework.pdf

So, would it be possible to use one BBB as I2C device?