DNS suffix not working when VirtualBox Host-Only Ethernet Adapter is active

[Rainer Meier]

I noticed that the VirtualBox Host-Only Ethernet Adapter is somehow screwing up correct DNS resolution on my hosts.

First I show you what happens before installing VirtualBox:

ipconfig /all shows the following for my Local Area Connection: ...

Connection-specific DNS Suffix . : mydomain.local

...

nslookup shows the following for a local server: C:\>nslookup server Server: server.mydomain.local Address: 10.0.1.6

Name: server.mydomain.local Addresses: xxxx:xxxx:xxxx:x::x

10.0.1.6

A ping to the host looks as follows: C:\>ping server

Pinging server.mydomain.local [xxxx:xxxx:xxxx:x::x] from xxxx:xxxx:xxxx:x:xxxx:xxxx:xxxx:xxxx with 32 bytes of data: Reply from xxxx:xxxx:xxxx:x::x: time<1ms ...

So the ping to the local server succeeds and uses the IPv6 address.

Now I install VirtualBox. As soon as the VirtualBox Host-Only Ethernet Adapter is installed the output of nslookup changes immediately:

C:\>nslookup server Server: server.mydomain.local Address: 10.0.1.6

Non-authoritative answer: Name: server Address: 67.215.65.132

The address returned corresponds to 67.215.65.132 which is the re-direct page for non-existent domains used by my DNS provider (OpenDNS).

So it looks like the DNS suffix is not attached to the request any more and therefore DNS resolving fails locally. Manually adding the DNS suffix still works as expected (same output as without the VirtualBox Host-Only Ethernet Adapter).

But when I try to ping 'server' it gets a little strange: C:\>ping server

Pinging server [10.0.1.6] with 32 bytes of data: Reply from 10.0.1.6: bytes=32 time<1ms TTL=64 ...

So somehow it does not try to ping the IP resolved by OpenDNS (67.215.65.132) but the local IP instead (which is not resolved by nslookup). The IPv6 address however is not used any more at all.

When I try to ping the full host name (server.mydomain.local) then it works perfectly. Also when I disable the VirtualBox Host-Only Ethernet Adapter within the network connections or the device manager and then either reboot or disable and re-enable my local Ethernet interface the problem disappears immediately and re-appears if I re-enable the Host-Only adapter. So there seems to be some problem with the DNS suffix when the VirtualBox Host-Only Ethernet Adapter is active.

I am running

• Microsoft Windows Vista x64 Business
• VirtualBox 2.2.0

[Rainer Meier]

I've found a work-around for this problem. It seems that Windows (at least Vista in my case) adds new network connections with higher priority than the existing on.e This causes the "VirtualBox Host-Only Network" connection to get higher priority than my already existing "Local Area Connection".

To change priorities follow this procedure:

• Go to the control panel
• Open "Network and Sharing Center"
• Click on "Manage network connections"
• Press left Alt-Key to open the menu bar
• Open the "Advanced Menu"
• Click on "Advances Settings..."
• Confirm UAC prompt
• In the dialog appearing move the "VirtualBox Host-Only Network" entry below your LAN connection
• Click OK

This is a work-around and not really a solution. Probably the installer should be enhanced to set lower priority for the new network connection.