I finally installed Mavericks on my 27" iMac and decided to do a multiple Thunderbolt bridge tests.
Here is the set-up.
In short, "it WORKS!" It is really plug-n-play. In my initial trial, I assigned IPs. It is not necessary to manually assign IPs.
I connected a 2012 13" MacBook Pro, 2013 15" Macbook Pro Retina, 2012 27" iMac. Both the Retina Macbook and iMac have dual Thunderbolt ports.
The Retina MBP acted as the hub for both the 13" and iMac. Once connected, all the machines can see each other. The 13" with it's single Thunderbolt connected to the 15" could see and access the iMac.
13" Macbook Pro
The 15" shows both my Thunderbolt ports active
Now for the tests.
On the 13" Macbook Pro, I could ping, mount and connect to my 27" iMac which was connected via the Retina 15".
As I mentioned above, I didn't need to assign any IP addresses. I called the machines up by their host names and IP address. So, for the 13", all I had to do was type in afp://169.254.216.89 or afp://iMac27.local and I was accessing the iMac.
Unfortunately, there is a small penalty loss when you go through another machine.
The first two iPerfs were the 13" connecting to the iMac.
5.24 Gbits/sec and 650 MB/sec.
When accessing the 15" Retina Macbook directly, iPerf jumped up to 7.16 Gbit/sec and 859 MB/sec.
I then pulled one of the cables off from the Macbook Retina and connected it to the iMac's second Thunderbolt port. Voila. It works. However, both the 13" and iMac's IP address re-assigned themselves. This was completely plug-n-play. I did not have to assign routes or anything to get the machines to see one another.
Still, these are impressive numbers no matter how you look at them. Now, this is definite proof a multi-user Thunderbolt IP network is viable.
Someone needs to make a Thunderbolt IP switch, hub, router ASAP! Lastly, Thunderbolt cables are dropping in price. I've gotten a few for under $25-30.