Virtual machine have no connection

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bormanjames
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Joined: 19. Sep 2021, 20:47

Virtual machine have no connection

Post by bormanjames »

Hello,

i will be brief, windows 10 host to linux vm (but os don't matter i have tried with windows and experienced the same issues).
connecting trough proxifier to test the enviroments we work on in different countries, proxifier have the option to resolve dns from socks, which is what we want, as soon as this function is enabled, our host work perfectly, but all vm stop having internet.

We have tried to change proxifier to use the dns automatically, but this leak our ip so it's not a go for us.

Before anyone start saying that this is a proxifier issue and not a virtualbox issue i specify that is only virtualbox that don't connect anymore, anything else works perfectly, browser, apps everything except virtualbox.

host windows 10 guest linux/debian, latest version of virtualbox.
thanks for any help
scottgus1
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Re: Virtual machine have no connection

Post by scottgus1 »

This may be because of how the VMs are networked. NAT and NAT Network go through he host's network stack and probably get Proxified. Whereas Bridged goes around the host's network stack and sets the VM independently on the LAN and may need to be Proxified independently of the host..

How are your VMs set to network?
bormanjames
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Re: Virtual machine have no connection

Post by bormanjames »

i am not sure i understand, sorry i am kind of new to virtualbox.

the vm's are all set to NAT, no changes made there all default.
I am trying to do some reverse engineering to understand why having the dns to be managed by the proxies should cut off the connection inside the vm, i am sure it's something on the network settings of the vm because i have tried with 4 different vms and 4 different os and they all behave the same.
scottgus1
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Re: Virtual machine have no connection

Post by scottgus1 »

NAT puts a 'router' between the VM and the host & LAN. Virtualbox Networks: In Pictures

I don't know enough about troubleshooting networks except basic connections. Check https://www.virtualbox.org/manual/ch06.html#network_nat and https://www.virtualbox.org/manual/ch09.html#changenat

Also try Bridged to the host's wired Ethernet adapter.
bormanjames
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Re: Virtual machine have no connection

Post by bormanjames »

All the links don't seem to fix the issue of the lack of connectivity unfortunately.

I have tried bridge connect the vm, but that bypass completely every vpn or proxy i have on the system.
So no solution is fixing the issue so far.
BillG
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Re: Virtual machine have no connection

Post by BillG »

I suspect that it is something in your network setup or in proxifier rather than VIrtualBox. If the vm is set to use NAT, the vm will behave just as a PC behind a NAT router behaves. Normally that means that the vm has access to any site which the host can access.

Does proxifier work for devices which are behind a NAT router or only for devices behind a firewall? What I see about name resolution in their online manual doesn't give me much confidence that it would work for NAT.
Bill
bormanjames
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Re: Virtual machine have no connection

Post by bormanjames »

BillG wrote:I suspect that it is something in your network setup or in proxifier rather than VIrtualBox. If the vm is set to use NAT, the vm will behave just as a PC behind a NAT router behaves. Normally that means that the vm has access to any site which the host can access.

Does proxifier work for devices which are behind a NAT router or only for devices behind a firewall? What I see about name resolution in their online manual doesn't give me much confidence that it would work for NAT.

It's not a network related issue as i have tested the same behavior on three different network and diverging the problem to proxifier isn't the right solution either as i have tested many virtualization environment and the only one that have issue is virtual box.

How pointing the dns to to be resolved through the proxy itself can cause the virtual machine to stop connecting to internet it's the issue, not mentioning that through this forum, i have seen others having the same issues and never got any solution about it, just pointing to the fact it's not a virtual box related issue, when it's 100% related to the way virtual box network needs to be setupped in order to work.

As i mention previously, the host works perfectly, but virtualbox denies the connection, there most be a way to setup virtualbox correctly.
scottgus1
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Re: Virtual machine have no connection

Post by scottgus1 »

Please keep in mind that simply because this problem only shows up when Virtualbox is running does not necessarily make it a Virtualbox problem. It could be an incompatibility between Proxifier and Virtualbox. This is not 'passing the buck' to Proxifier. It is pointing out another place where the problem may be besides only Proxifier or only Virtualbox. It's like if one tries to take a United States electrical device to another continent and finds that the plug won't fit the electric outlet. Is the problem with the device or with the outlet? Neither. It's the incompatibility between the two that needs to be bridged. We won't say "It's a Proxifier problem" until we are sure the incompatibility can't be bridged.

Seeing that there may not be many folks who use Proxifier here on the forum, you'll have to be a lot more descriptive in how Proxifier interfaces with and controls the network. Also be more descriptive in what you are doing to troubleshoot:
bormanjames wrote:All the links don't seem to fix the issue of the lack of connectivity
is not descriptive enough. What exactly did you do to test what each link said? What does 'ipconfig /all' or 'ip address' say in each host or VM?

Also, BillG's thought on Proxifier & NAT was completely missed due to continued worry that we're just going to pass the buck. Let us set aside the concern about us saying it's a Proxifier problem. Bill was not passing the buck. He was pointing out an real possible compatibility concern that Proxifier won't work through a NAT router, just like a US NEMA 5-15 won't fit in a UK BS 1363 . Did you notice Bill's concern and can you please comment on it from your more in-depth knowledge of Proxifier?

One thought: Do you have multiple PCs on your LAN? When you enable Proxifier, do all the LAN PCs get Proxified? If so, then if you set the VMs to Bridged, then confirm that the VMs all have network access when the LAN is un-Proxified, then the VMs should be Proxified like all the other LAN PCs when you enable Proxifier. Bridged puts the VM on the LAN like any other physical PC. However, I have seen some Linux OSs not notice the change in network from NAT to Bridged, etc, and need to be manually reset.

I would recommend setting the VMs to Bridged while Proxifier is off. Confirm or reset networks on the VMs so you get full LAN and internet access on each VM same as the physical PCs get: same IP address range, same gateway, etc. Then when each VM resides on the LAN in the same way the physical PCs do, then enable Proxifier and do to each VM what you have to the physical PCs to make them honor Proxifier.
bormanjames
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Re: Virtual machine have no connection

Post by bormanjames »

scottgus1 wrote:Please keep in mind that simply because this problem only shows up when Virtualbox is running does not necessarily make it a Virtualbox problem.


Absolutely, but proxifier works with virtualbox, i don't have connection or incompatibility issues, the problem start only when proxifier enable the resolve the dns through proxy, which in this case works on the host machine, but not on virtualbox, this is baffling me.
scottgus1 wrote:Seeing that there may not be many folks who use Proxifier here on the forum, you'll have to be a lot more descriptive in how Proxifier interfaces with and controls the network
Proxifier can be setupped with rules, to follow the needs of the machine, but in my case i simply leave proxifier to manage the entire system connection, it uses in my case socks5
scottgus1 wrote:What exactly did you do to test what each link said? What does 'ipconfig /all' or 'ip address' say in each host or VM?
and ipconfig (when on a windows vm) gives the exact ip of proxifier except when i resolve the dns with proxifier in that case doesn't ping, there is zero internet in the vm.
The issue is that i am not a coder so considering that, i don't feel very confident in going writing lines of code in cmd, to realize i make things worst as i don't find any specific command inheriting the dns issue in the manual pages.
scottgus1 wrote:Bill was not passing the buck. He was pointing out an real possible compatibility concern that Proxifier won't work through a NAT router,
there is no compatibility issue between virtualbox and proxifier, i am very certain, that it's just a matter of setting up virtulbox slightly differently, because in proxifier there are really 2 switch and that's all.

scottgus1 wrote:One thought: Do you have multiple PCs on your LAN? When you enable Proxifier, do all the LAN PCs get Proxified?
i do, but proxifier don't cover and entire lan, just one single computer, sort of what a vpn would do.

scottgus1 wrote:If so, then if you set the VMs to Bridged, then confirm that the VMs all have network access
bridged connection simply bypass everything, vpn, socks etc and go straight to the main router leaking the entire ip address.

to conclude, the machine read every single change and virtualbox respond like a clock, there is literally no issue in connectivity, the problem most be in the way the network need to be setup in virtualbox to allow proxifier and socks to let the vm online.
scottgus1
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Re: Virtual machine have no connection

Post by scottgus1 »

OK, good, we have a lot more info here!
bormanjames wrote:proxifier don't cover and entire lan, just one single computer, sort of what a vpn would do.
So Proxifier seems to run as an app on the computer, like a VPN or firewall, with rules that define the computer's behavior. This seems to me to knock Bridged out of the running, then, because Bridged does bypass everything. It's NAT or bust.
bormanjames wrote:proxifier works with virtualbox, i don't have connection or incompatibility issues, the problem start only when proxifier enable the resolve the dns through proxy, which in this case works on the host machine, but not on virtualbox
So when Proxifier is not resolving DNS through the proxy, then the VM can connect?

Note please that:
scottgus1 wrote:What exactly did you do to test what each link said?
is still not answered. Curious that your problem revolves around resolving DNS and there just happens to be a link above that has some info on resolving DNS in Virtualbox NAT, that we have not gotten specific results regarding what you did to try the suggestions..
bormanjames wrote:i am not a coder so considering that, i don't feel very confident in going writing lines of code in cmd
You'll have to get used to it, especially with a Linux OS. Google up and get terminalling! :lol:
ip address in the Linux OS terminal provides the same info as "ipconfig /all" in Windows command prompt.

If the results from your further investigation of the above links (which will be described clearly and explicitly so we can see what was tried :) ) does not result in proper behavior of the VM's network, I think we will need to see the actual output of 'ipconfig /all' on the host and 'ip address' in the VM when Proxifier is not resolving DNS and when it is. That will be a set of 'ipconfig /all' and 'ip address' when Resolving DNS is off and full VM network is available, and another set of 'ipconfig /all' and 'ip address' when Resolving DNS is on and full VM network is blocked, please.
bormanjames
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Joined: 19. Sep 2021, 20:47

Re: Virtual machine have no connection

Post by bormanjames »

bormanjames wrote:So Proxifier seems to run as an app on the computer, like a VPN or firewall, with rules that define the computer's behavior. This seems to me to knock Bridged out of the running, then, because Bridged does bypass everything. It's NAT or bust.
Preciselly
bormanjames wrote:So when Proxifier is not resolving DNS through the proxy, then the VM can connect?
Again correct, the issues start when i ask proxifier to resolve the dns, if i leave that option off going on any ip checker will give the correct ip address, but on the pubblic ip it will display the vpn ip, a very exhaustive analysis of an ip check can be done in browserleak for example.
scottgus1 wrote:What exactly did you do to test what each link said?
I am trying to fiddle between the cmd commands, but what i meant is that without a more indeep knowledge of the outcome of each individual command, i am afraid i might make matter worst.
bormanjames wrote:You'll have to get used to it, especially with a Linux OS. Google up and get terminalling! :lol:
Aha i am starting to realize that :)
bormanjames wrote:That will be a set of 'ipconfig /all' and 'ip address' when Resolving DNS is off and full VM network is available, and another set of 'ipconfig /all' and 'ip address' when Resolving DNS is on and full VM network is blocked, please.
I am going to do that now, and thank you very much for the help by the way.
fth0
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Re: Virtual machine have no connection

Post by fth0 »

bormanjames wrote:Absolutely, but proxifier works with virtualbox, i don't have connection or incompatibility issues, the problem start only when proxifier enable the resolve the dns through proxy, which in this case works on the host machine, but not on virtualbox, this is baffling me.
Well, this is probably one of the reasons why Name Resolution in the Proxifier documentation recommends against it. ;)

Seriously, the Proxifier documentation explains that it then delivers a 127.8.*.* "(fake) IP address", that is only valid on the local computer (*). Since the VirtualBox VM is "another computer", the delivered IP address is then only valid within the VM. This is a good strategy to sell more Proxifier licenses, BTW. The VirtualBox DNS proxy modes will not make a difference, because they will not modify the resolved destination IP address.

(*) IP packets sent to an IP address in the 127.0.0.0/8 network (localhost) are sent to the loopback network interface and will not leave the computer.
bormanjames
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Re: Virtual machine have no connection

Post by bormanjames »

fth0 wrote:Seriously, the Proxifier documentation explains that it then delivers a 127.8.*.* "(fake) IP address", that is only valid on the local computer (*). Since the VirtualBox VM is "another computer", the delivered IP address is then only valid within the VM. This is a good strategy to sell more Proxifier licenses, BTW. The VirtualBox DNS proxy modes will not make a difference, because they will not modify the resolved destination IP address.
wtf! lol that explain why the host machine works and the virtual machine doesn't and was right there, then now it's a matter of understanding why my machine leaks the vpn ip on host and virtualmachine, but it's not a virtualbox issue anylonger.

Thanks for that explenation.
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