Ticket #2760 (new enhancement)

Opened 12 years ago

Last modified 5 years ago

Feature request: direct tun/tap support not available since 2.1.0

Reported by: schinkelm Owned by:
Component: network/hostif Version: VirtualBox 2.1.0
Keywords: tap Cc:
Guest type: other Host type: Linux

Description (last modified by vushakov) (diff)

It was very nice that virtualbox supported the direct usage of tun/tap interfaces and NOT used another driver which means one more possible point of failure or incompatibility. That was a major advantage compared to other virtualisation systems (vmware for example). Now there is possibly a "double bridge" (on in the "filter driver" and one in the working and very stable kernel mainline bridge code) which means double work, possibly worse performance.

Why reinvent the wheel? Please readd direct tap support again!

Change History

comment:1 Changed 12 years ago by sandervl73

  • priority changed from major to minor
  • Summary changed from direc t tun/tap support not available since 2.1.0 to Feature request: direc t tun/tap support not available since 2.1.0

comment:2 Changed 12 years ago by grayfox

I am running VB 2.1.0 on Fedora 10 with a WinXP guest. My network connectivity is via a wireless router.

I used a tap interface with parprouted to implement 'host networking' in versions prior to 2.1.0.

The tap interface appears to *not* be working ( even though tap0 appears in the interface list in the GUI).

I can use the new host networking and the wireless interface ( eth1 ) and everything appears to be working, however XP keeps complaining about a duplicate IP.

Has the tap interface been removed or is it simply broken and apt to be fixed in a future version?

comment:3 Changed 12 years ago by frank

What does that mean, the TAP interface is not working? What happens when you attach a hostif to a TAP device?

comment:4 Changed 12 years ago by grayfox

My experience is that the guest thinks networking is available but there is no connectivity to any other machine on the local network.

ie I cannot ping/ftp/http to any other machine and other machines cannot contact the guest.

I set the tap up in rc.local with # /sbin/sysctl net.ipv4.ip_forward=1 VBoxTunctl -b -u jerry /sbin/ip link set tap0 up /sbin/ip addr add dev tap0 parprouted eth1 tap0

On boot tap0 is available up and running...eth1 is my wireless connection

when I configure the guest I choose tap0 as the host interface.

In the guest winxp network config I use a static IP of and the console command:

ipconfig /all

shows everything looks good...

But external networking does not work.

The same configuration worked fine in VM 2.0.6.


comment:5 Changed 12 years ago by vsu

Another problem with the new host interface implementation is that it does not seem to support any access control - if the vboxnetflt module is loaded, any user in the "vboxusers" group can attach a VM to any network interface on the machine. With the old tap implementation it was possible to give tap access just to particular users (and the tap traffic could be filtered further by iptables/ebtables rules).

Yes, the new implementation is simple to configure in simple cases - but it does not support some more complex configurations at all. So please restore the old tap implementation in addition to the new one (then people who need access control could disable loading of the vboxnetflt module and use just /dev/net/tun).

comment:6 Changed 11 years ago by frank

  • Component changed from network to network/hostif

comment:7 Changed 11 years ago by ksteuernagel

I also found that the old TAP networking was easy and suppported also the internal connection between the host and guest without a bridge to be setup. Now with 2.10 (2.12), this doesn't seem to work anymore. My setup does have two interfaces. Let's call the one "external" which is connected to a bridge on WinXP and through that to the physical Ethernet port. The other is the "internal" which justs connects Guest and host so that I can ssh into it "locally".

  • NAT doesn't work here as there is no interface
  • Internal doesn't work as it only connnects guests but not the host
  • Host networking doesn't work as I would need another physical interface

comment:8 Changed 5 years ago by vushakov

  • Type changed from defect to enhancement
  • Description modified (diff)
  • Summary changed from Feature request: direc t tun/tap support not available since 2.1.0 to Feature request: direct tun/tap support not available since 2.1.0
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