VirtualBox guests causing DNS issues on host and guests

[omega1]

Hi all,

I am having significant issues with VirtualBox which appears to be causing DNS issues on both the host and guest machines which seems to happen more during heavy file transfer on guest machines.

I have a Windows 7 64 bit Professional Host and have two Windows XP guests. My VirtualBox is 4.3.4r91027.

The issue is that after a few hours of the guest machines copying lots of files (via a robocopy script which uses Netdrive to connect to an FTP site) both the two guest machines and also the host machine stops resolving DNS and http requests. I thought that the only way for me to recover was rebooting the machine, leading me to believe that the issue was with the host install of Windows 7.

I have now discovered that if I close down the VirtualBox machines the DNS resolution stats working again on the host machine. Therefore I suspect that VirtualBox is causing the problem I am experiencing.

I 'think' that is happening when the heavy transfers are initiated on the guest machines as if I leave the guests booted into desktop, it doesn't appear to happen.

The Windows 7 host is connected by wired connection to the router with a static IP address and other machines on the router do not have the problem so it is definitely isolated to the host machine.

The guest machines network settings are 'NAT' and 'I have 'Cable Connected' and have a number of ports forwarded.

I'm happy to provide more info if requested to see if I can find out what the problem might be.

Thanks in advance for any assistance you can provide.

[socratis]

I suspect that VirtualBox is causing the problem I am experiencing.

Why do you suspect that?

What if you had two *physical* machines that were causing network congestion? I once had a rogue application that after two hours of running would either cause *all* of the network traffic to come to a halt, or I would have to restart it and fix the problem. A newer version of the application fixed it...

[omega1]

HI,

OK, maybe quoting VirtualBox as 'causing the issue' was not completely correct.

The fact is that I appear to be having issues when there is high traffic on the guest machines. If the guest machines have little traffic, all appears to be OK.

I have tried both Netdrive and Webdrive and I experience the exact same problem, which is when I have multiple file transfers going on, after approx one hour, I get what appears to be a DNS error where I am unable to browse Internet on either the guest machines or the host machine either. Shutting down both the guest machines then solves the problem and I am again able to browse and DNS resolves o nthe host machine. If I restart the guest machines all is OK with them also, until I start the file transfers and I'm back to square one.

What appears to be happening is that there is some conflict/issue when I start the guest machines to carry out large file transfers (not large files, but a large number of files of varying size).

I have had Netdrive working on the host machine for a while and do not experience this problem, so I suspect there is some kind of problem related to VirtualBox, hence me posting here.

I'd really appreciate any pointers as to how to solve this or at least where to start looking...

Thanks in advance.