I2C between Arduinos without Master I am working on a library for some Arduinos that should talk between each other.
The aim is that I can load the same binaries onto each Arduino. The I2C ID will be set by DipSwitches.
So far everything works pretty nice but once a while everything gets stuck.

I am not asking you to resolve and debug my code, but I am not sure if i have done something completely wrong:

To make all Arduinos interchangeable I have no Master (Wire.begin()) in my I2C Bus.

I read, that the Master would be responsible for the pulse on the Clock line. As I have no Master in my setup maybe that is the reason for the instability.

Can anyone confirm that connecting some I2C Arduinos without master is something that cannot be done? (or do I have to look for some other reason)
You have to have a master for an I2C bus to work.  Can't you allocate one of the dip switches to define the master?

Edit to be able to remove the downvote 
Nick his answer seems to imply that you do not need masters but that is wrong. 
What Nick is saying is that you can swap masters over time.
But each time there is communication there is a master.
So the statement "You have to have a master for an I2C bus to work" is 100% right.
As I misunderstood this myself I downvoted this answer. I hope this edit will enable me to remove my downvote and add a upvote.