Host-only adapter conflict - Vagrant 2.2.5 / VirtualBox 6.0.8 / Win10 /

[Dan C. Wlodarski]

To test Vagrant 2.2.5, I attempted to start a hashicorp/precise64 box using the instructions detailed here:

https://groups.google.com/d/topic/vagrant-up/gXFpt-joRco/discussion

The "vagrant up" command fails with the following error:

A host only network interface you're attempting to configure via DHCP already has a conflicting host only adapter with DHCP enabled. The DHCP on this adapter is incompatible with the DHCP settings. Two host only network interfaces are not allowed to overlap, and each host only network interface can have only one DHCP server. Please reconfigure your host only network or remove the virtual machine using the other host only network.

The machine has no problem running a self-created Ubuntu 18.04 guest OS with networking.

Please see the attached files for the outputs of:

• vagrant plugin list
• vagrant destroy -f
• vagrant up --debug

as well as the Vagrantfile resulting from:

• vagrant init -m hashicorp/precise64

Ultimately, this is an attempt to troubleshoot a networking error in another Vagrant VM.

Please advise.

[Dan C. Wlodarski]

By way of an update: I've upgraded VirtualBox to 6.0.10.

In an attempt to isolate some variables, I switched to a non-minimal precise64 base box, then added the following statement to the hashicorp/precise64 Vagrantfile:

config.vm.network "private_network", ip: "192.168.56.100"

Somehow, this prevented the "VERR_INTNET_FLT_IF_NOT_FOUND" VBoxManage error mentioned in my original post, allowing VM to boot. The provisioning successfully SSH'd into the running VM to update the system via apt and install the VirtualBox 6 guest additions. Adding the statement:

config.vm.network "forwarded_port", guest: 22, host: 2020

also suppressed the error.

Bolstered by my success, I tried to provision some CentOS 6.10 & 7.6 VMs (based on bento/centos-6 and bento/centos-7, respectively). The VMs provisioned from these base boxes returned the same "VERR_INTNET_FLT_IF_NOT_FOUND" VBoxManage error until the config.vm.network properties were set.

Perhaps an incompatibility between Vagrant v2.2.5 and VirtualBox 6.0.x?

[Dan C. Wlodarski]

Final report: Seems there's a bug in the VirtualBox 6 virtual host-only adapters that persists across instances of the adapters but not across installations of VirtualBox. By deleting all virtual host-only adapters, uninstalling VirtualBox (ensuring no files are left behind), restarting, and finally reinstalling VirtualBox, the adapters created & configured upon "vagrant up" now work.

Will investigate this virtual adapter bug with Oracle Support (lol).