How to run multiple guest OS in QEMU?

This weekend I've been fiddling with QEMU. I've installed OpenBSD on a single image and wanted to have two instances of it communicating via network. Installing the system was easy, but the networking setup was quite a pain. See how I did that...

To make QEMU instances communicate with each other I needed to plug them to a "network". That's why I've created a bridge to which Virtual Instances would connect to. I've used the following script:

Then I just needed to start Qemu with this command line:

Since I've set up bridge for Qemu instances, I've plugged TAP interfaces into it. That's why I've needed to specify this in my qemu exec line. I've also added macaddress setting since both my instances were getting the same one.

And that's all! It works like a charm. Now on to some harder things!