VMWare Workstation Pro 15 - NAT drops after a few hours

[mehetmet]

Hello:

• I am running VMWare Workstation Pro 15.1.0 Build 13591040
  • My host machine is Windows 10, 64-bit  (Build 18362) 10.0.18362 with an Ethernet connection active.
    • Windows System Info states:
      • Edition WIndows 10 Pro
      • Version 1903
      • OS Build 18362.295
  • My guests are a Kali-Linux image and a Windows 10 image. 
  • I have VMnet8 set up as a NAT in the Virtual Network Editor, "Connect a host virtual adapter to this network" is checked, as is "Use local DHCP service to distribute IP address to VMs".

Both guests have the Network Adapter Network Connection set to NAT, and Connect at power on and Connected are both checked.

When I fresh boot the host machine, then boot my guests, the guest VM's can communicate with each other, the host, and the internet, as expected.  However, after some intermittent time period, somewhere between 2-4 hours, my guest VM's (both the Kali and Windows 10) will lose all connection to the internet.  Restarting the network adapters seems to have no effect.

When this network drop occurs, the following statements are true:

• the guests can still communicate with each other (ping from one machine on the NAT to the other works, in both directions, as does SSH/port 22)
• The guests can still communicate with the host and the host with the guests (using ping and SSH)
• The guests can no longer reach any external address -- All web pages fail to load
  • I have checked if it is DNS as well, but if I ping a public IP such as 8.8.8.8 nothing returns.
• The host machine can reach the internet without issue, is able to load web pages and ping IP's including 8.8.8.8.
• The following services are in the "Running" state on the Host
  • VMware Authorization Service
  • VMware DHCP Service
  • VMware NAT Service
  • VMware USB Arbitration Service
  • VMware Workstation Server

The only workaround I have found is rebooting the host machine.  After the host reboots, and I bring the guests back online, the guests can communicate as expected.  Then again, 2-4 hours later, this process repeats.

Has anyone else seen this behavior and/or have any suggestions?

[continuum]

There is a nicer workaround than rebooting the host.

I had the same problem with earlier versions and noticed that the vmware NAT service is not very stable.

So create a batchfile - store it on your desktoop and run it via right-click "run as admin"

You need this 2 lines in the cmd-file:

---------------------------------------------

net stop "VMware NAT Service"

net start "VMware NAT Service"

----------------------------------------------

store those 2 lines as "restart-nat.cmd"

If this works it will fix the situation without stopping the VM or restarting the host

[mehetmet]

I'll have to try that out.  I didn't even think to try restarting the service, I just verified that it was running.

I'll let you know if that works.

[mehetmet]

Following up here -- It seems as though restarting the VMWare NAT service does not resolve the issue. 

[continuum]

That used to work in earlier versions ...

Maybe you need to restart VMware DHCP service as well ...

[mehetmet · Accepted solution]

Following up a bit later, as I think I have found the cause and thus a solution to this issue.

When I configured my NAT settings in Virtual Network Editor, I changed the Subnet IP of my NAT.  This inherently shouldn't be an issue, but in doing so I also had to update the Gateway IP.

I changed from the default configuration to use the 192.168.100.0/24 Subnet, and per most "standard" networking practices then also updated the Gateway IP to 192.168.100.1.  This I believe was the root cause of my issue, as it was conflicting with something else (the NAT adapter IP itself maybe?). 

I noticed this after resetting to default settings and seeing that the default NAT gateway IP was actually x.x.x.2, not x.x.x.1.  I adjusted my Subent to 192.168.100.0/24 as I desired, and then updated my Gateway IP to 192.168.100.2 to match and haven't had any issues since.

I didn't find this documented anywhere, so hope this may help someone else in the future. 

[Mits2020]

Thank you for remembering and taking the time to post your solution in the Community!

I'd be happy to live in your Universe, where 10 months are just "a bit later" In our universe, 10 months is an eternity!

[miechovy]

Hi! If I may to help a Vmware community, I have to tell you that your solution is worked to me too. Many many thanks.

My topic: https://communities.vmware.com/t5/VMware-Workstation-Pro/Multiple-VMs-network-issue/m-p/2862876/high...

I'm using Vmware 16 and Debian 11 as a host.

[Julian_Lim]

Environment: VMware Workstation 15 Pro

HostOS : Ubuntu 18.04

GuestOS: Windows Any

[ STEP 1 ]

     $ sudo /usr/bin/usrvmware-netcfg

        Name: vmnet8 ,

        Type: NAT,    (NAT Settings : Gateway IP: 192.168.189.2)

        External Connection NAT,

        Host Connection : vmnet8

        DHCP : yes    (Use local DHCP service to distribute IP addresses to VMs)

        Subnet IP Address : 192.168.189.0   ( Subnet mask: 255.255.255.0 )

        MTU : -

[ STEP 2 ]

     Vmware Menu > Settings > Hardware Tab > Network Adapter > Network Connection > Custom: [/dev/vmnet8] > Save

[ STEP 3 ]

     Change your guest OS IP: 192.168.189.100, Subnet Mask: 255.255.255.0, Default Gateway: 192.168.189.2, DNS: 8.8.8.8

It works well for me.