VMware NAT Service Consuming Excessive Network Bandwidth V14.1.3

[Cryptonoetic]

After installing the recent VMware update (14.1.3), the NAT service has been consuming excessive network bandwidth. Windows virtual machine networks are configure as metered connections. No apps in the virtual machines access external networks (e.g., I'm not running a browser from the virtual machine). Resetting the entire VMware network environment from the Virtual Network Editor had no effect. Google searches all seem to be focused on dealing with poor NAT performance, not excessive bandwidth consumption. Network traffic is over WWAN so it's costly and I need to plug this leak soon.

The NAT2 snip shows network traffic for the last 5 days. The NAT snip shows network traffic for the last 3 hours. Thanks in advance for any resolution guidance.

[wila]

Hi,

My guess would be that your guests by itself are downloading that data. For example for windows update, or to chat back to Microsoft.

If you don't want your guests to access the internet, then probably the best solution would be to use a host only network instead of a NAT network.

--

Wil

[Cryptonoetic]

Hello,

I pointed out in my question that all networks in the Windows VMs are set to metered. Hence, there are no Windows OS, no OneDrive nor MS product background downloads. Every time I start a VM, the first thing I do is check to make sure the network 'metered' attribute is active. -Greg

[wila]

Hi,

Yes I read that.

The NAT service by itself does not consume any bandwidth, if it does then that would be a huge product defect.

So normally it is something in your guest that is still consuming the bandwidth you are having issues with.

Regardless of the "set as metered" configuration.

This is why I suggested "Host Only" networking as then your guests cannot connect to the network outside of your host.

That should solve your bandwidth issue, but if your guests still have to connect to the internet then that won't work.

I do not know what you installed in those guests, so I cannot guess what is using the bandwidth.

Maybe it would help to use a packet sniffer to see what is using this bandwidth?

Sounds like that will be the only way to figure it out if you want to continue using NAT.

--

Wil

[DanTremonti]

I have been facing the same issue running UBUNTU 18.04.5 with Windows 10 host machine. I have no idea what a constant 6MBps data is consumed for, by VM NAT services. I have already updated UBUNTU and I'm not using any browsing related task either. Any proper insight is appreciated.

[wila]

Hi,

As said to the TS, the NAT service itself does not consume any bandwidth. It is the vehicle that your guest OS uses to connect to the network.

So you would normally be looking at your guest OS as to what is connecting to the internet.

For example in ubuntu you could see what is connecting to the internet using:

sudo lsof -i

( see How to Use the Linux lsof Command )

some tools to see bandwidth / network usage in your guest:

https://stackoverflow.com/questions/368002/network-usage-top-htop-on-linux

If that does not help then you would have to look into sniffing the network traffic at host level and make network captures to see where it comes from.

Doing that is fairly technical I'm afraid.

--

Wil