This should be applicable to real world (physical devices) not just virtualized environment. The topology is simple:
+----------------------------+
| The Host |
| -------- |
| Router |
+----------------------------+
| |
+-----+ +-----+
192.168.1.1 | br0 | | br1 | 192.168.1.9
+-----+ +-----+
| |
Mask: 192.168.1.0/29 | | Mask: 192.168.1.8/29
+--------------+ +----------+
| | |
| | |
+--------------+ | +---------------+
| VM 1 | +----+ | VM 3 |
| 192.168.1.2 | | | 192.168.1.10 |
+--------------+ | +---------------+
+--------------+
| VM 2 |
| 192.168.1.3 |
+--------------+
The Details
The goal is to connecting VM in different subnet so they can talk to each other. Btw, I'm using Virtualbox for this playground. Here's the breakdown from the schema above:- The Host had two interface br0 and br1 (Both are virtual)
- The schema using two subnet 192.168.1.0/29 and 192.168.1.8/29
- The Host had two bridge interfaces and three TAP interfaces (for each VMs)
- tap0 for VM 1, tap1 for VM 2 and tap2 for VM 3
- tap0 and tap1 attached to br0 and tap2 attached to br1
