Raise maximum number of Host-Only networks

[UglyPercy]

The current limit of 8 is plenty for any reasonable application, but there are a lot of unreasonable applications out there. In my case, I need at least 60 Host-Only networks. I was able to achieve this by editing the VB OSE source code, but it would be nice if this was an official enhancement.

[Technologov]

Host-Only networks is a feature for newbies IMO.

Professionals can use TUN/TAP interfaces. I recommend you to create 60 TAP interfaces on host, and bridge VMs to those. This should work on any host OS.

For VBox 3.2.x on Linux hosts, you have even a simpler solution: VDE. (Virtual Distributed Ethernet)

​http://wiki.virtualsquare.org/index.php/VDE_Basic_Networking

Both VDE and TUN/TAP solutions are endless number of interfaces per host, the only limit being 8 NICs per VM.

-Technologov, 14.6.2010.

[UglyPercy]

Not sure what you mean by "professionals can use TUN/TAP interfaces" -- is there some sort of licensing or certification required to get permission?

I don't know anything about TUN/TAP interfaces, or VDE's, but perhaps they could work in my configuration. In fact, they might turn out to be higher-performance than the VB Host-Only networks. Will have to investigate.

[Technologov]

No certification required. Just knowledge.

I wrote an article on this topic few years ago.

​http://chorgan.provo.novell.com/lfl/.html/virtualbox.html

See Chapter: "Intermediate Topic: Networking via Host Bridging"

This explains how-to setup TAP interfaces on Linux host and connect them to VirtualBox. The info is correct for openSUSE 10.2/10.3 Linux hosts and VirtualBox 1.3.x series, so some modifications (in small details) may be necessary for modern systems.

-Technologov

[UglyPercy]

Thanks for the help, Technologov, but I don't see "tunctl" as being available for CentOS 4.2 in the usual RPM repositories. I suppose I can try to built it myself.

[UglyPercy]

Well, thinking about this more: if TUN/TAP interfaces can be easily created in modern guest OS's, and can take the place of Host-Only adapters while (possibly) providing greater performance and/or functionality, they should be listed in the VB documentation -- there should be a paragraph in the description of Host-Only networks saying that "You might try a TUN/TAP interface instead, because it might work better". Same goes for VDE.

Now, my evaluation of VB is complete, and I don't believe I'm going to be able to take the time, but I wish I could set up the TUN/TAP and VDE solutions and get some benchmarks. That's the only way to see if they're better than the Host-Only networks (which are, in my tests, support about 40% less traffic than Big Hypervisor Company's solution ("iperf" in a loop into and out of a "brctl" bridged VM via two Host-Only adapters)).