Win7 guest can access some network stuff, not others

[bittergeek]

I'm running Xubuntu 11.10 64-bit with VirtualBox 4.1.8. I need to install a Win7 guest. It installs okay, but won't access certain network resources. Here's a rundown of things I have tested:

Can't do:
-Access any website (local or internet, Firefox or IE)
-Map drive on NAS device

Can do:
-Ping local hosts
-Ping internet hosts
-nslookups
-Join to domain
-Map drives on domain servers
-Oddly enough, I can connect to web servers with telnet on port 80

I have tried both 32-bit and 64-bit Windows. I have tried with and without Guest Additions. I have tried an older version of VirtualBox (4.1.2). I have tried a Linux guest and it works fine with everything.

It is set up with bridged networking.

And just for fun, here's an odd thing about trying to access web pages: it will generally load some unstyled content but nothing else if even that. And the NAS device will ask for authentication but won't load and eventually errors out.

Any help would be appreciated!

[Perryg]

Is this a corporate network?

[bittergeek]

Yup. The issue happens on a fresh install of Windows before being joined to the domain, though.

[Perryg]

I thought so. The things that are haunting you should be addressed with you IT department. Bridged mode acts like another PC on the LAN.

[bittergeek]

Yeah, I am the IT department. :c)

I have to admit I'm not 100% sure it's a problem with VirtualBox given that an old version gives the same problem and after googling around I haven't discovered anyone else with the same issue, but the fact that Linux guests work fine makes me unsure.

Any other advice other than "ask someone else"?

[Perryg]

You are the IT department. Ok then look for issues with firewalls of the GPO of the domain. Does the Windows guest need to have anything special?
You should be able to track this down with wireshark (my preference, use what you like) to see where the packets are failing.

Usually when I see this in a corporate LAN the reasons are always permission of one kind or another, but you would know more about how you set up the LAN for user access. Like I said in Bridged mode the guest will appear as another PC on the LAN so I would look at it from that angle and not why one worked and not the other. What would you do if someone hooked up a new Windows PC in the LAN.

[BillG]

Once you have set the NIC to bridged mode, what happens with the networking really doesn't have much to do with VirtualBox. The NIC will behave just like the NIC in any other machine on the same network. All VirtualBox does is install a filter driver so that the NIC in the virtual machine can use the physical NIC in the host. This filter makes sure that traffic for the vm's MAC address goes to the vm OS and traffic addressed to the host's MAC goes to the host OS.

If you are getting unusual things happening with the networking in the vm, the VBox filter driver would be one of the last things I would suspect. If it is having problems with the NIC driver for the physical NIC the problems are major (like no traffic on one NIC or the other), not fiddly little problems like yours, which sound like normal network config problems to me.

[bittergeek]

I like the Wireshark suggestion!

It is showing a lot of lost and duplicate packets... Both with HTTP and SMB. When following the TCP stream, I see the web server sometimes return a "200 OK" but what I get after that is hit and miss. Sometimes the <title> tags come through, but not others. I also see packets labled as malformed.

If I were looking at this as if someone came in and hooked up their Windows PC, I would point my finger at the NIC or cable. Malformed and missing packets is screaming a problem on layer 1; the ones and zeroes aren't making it from point A to point B in the right order or not at all. But the NIC is virtualized and the host machine is chugging along without a problem...

[Perryg]

What adapter did you choose for the guest?

[bittergeek]

Just the default Intel PRO/1000 MT Desktop, but I've also tried the other Intel versions like "MT Server." I tried PCNet-FAST III but Windows never found drivers for it.

[Perryg]

It is really hard to diagnose network problems when not in the room. Add hundreds/thousands of miles and.. you get the point.
Could it be a bridge issue? Maybe but I don't see these at all any more. I would suggest to set the guest to use NAT and see what happens but that is going to totally change the dynamics of the network and not sure it will really show what the issue is. I only use the VirtIO (paravirtual)drivers myself because they are so much faster. Maybe you can snag them and see if it fixes your issue as well.

[bittergeek]

If I switch from Bridged to NAT everything works. I'm not sure if Active Directory is going to be happy having a client behind NAT, though...

So what can break bridging but not NAT?

[bittergeek]

I understand trying to troubleshoot networking problems remotely. Ugh...

VirtIO has the same problem. Unless anyone has any ideas about why bridging could be broken when NAT works, I'll just work with NAT and see if it functions like I need it to for now.

[Perryg]

Yes I do have another question. Which VirtualBox did you install? Was it from the distro or did you get it from VirtualBox.org?

[bittergeek]

I got 4.1.8 from VirtualBox and when I tried 4.1.2 it was from the distro.