Jtdylktuy

I have VMware Fusion running on macOS (host) and 1 VM with Windows 10 as guest. Networking is set to Shared (ie NAT).

I would like to connect to a webserver running on the Windows 10 VM, on port 8888.

I gave the VM a fixed IP address, by editing /Library/Preferences/VMware Fusion/vmnet8/dhcp.conf and adding:

host Windows8x64 {

    hardware ethernet 00:0C:29:86:EB:52;

    fixed-address 192.168.80.101;

}

Next, I edited /Library/Preferences/VMware Fusion/vmnet8/nat.conf and added:

[incomingtcp]

9888 = 192.168.80.101:8888

Restarted VMware networking using the commands:

sudo /Applications/VMware Fusion.app/Contents/Library/vmnet-cli --stop

sudo /Applications/VMware Fusion.app/Contents/Library/vmnet-cli --start

On the Windows VM, I refreshed the network address using DHCP to make sure it received the fixed address (which is outside the range of DHCP leases).

All firewalls on Windows have been disabled, and the network locations have all been set to private.

When I try telnet 192.168.80.1 9888 to see if I can contact the client machine from the host OS, I would expect either the connection to be established, refused or eventually timed out. To test things out, I have ncat running on the client (ncat -4 -l -t -v 192.168.80.101 8888).

This is the output of the telnet command:

telnet 192.168.80.1 9888

Trying 192.168.80.1...

Connected to 192.168.80.1.

Escape character is '^]'.

and after some time...

Connection closed by foreign host.

In other words: the connection was established, but the strange thing is that I'm seeing no activity whatsoever on the Windows client. I've disabled all other networking on the host to make sure that it's connecting to the VMware network.

I found this in the logfile /var/log/vnetlib whenever the VMware network is (re)started:

VNLNetCfgLookupNATPortFwd - List of NAT forwarded ports is empty

VNLNATReadPortForward - Failed to read TCP port forward config info.

VNL_StartService - Started "NAT" service for vnet: vmnet8

In /Library/Preferences/VMware Fusion/vmnet8/networking, I found the following (auto-generated) line, indicating that the configuration change for the port forwarding seems to have been read correctly:

add_nat_portfwd 8 tcp 9888 192.168.80.101 8888 

At this point, I'm at a loss.

Version info

• macOS Mojave 10.14.3


• VMware Fusion 11.0.2


• Windows 10 Pro version 1809

TLDR

• "Something" is accepting a connection to the mapped port, but the traffic is not reaching the guest VM, even though all firewalls have been disabled.




• Port forwarding and fixed IP assignment seem to be correct, but the log file is indicating an error.

Update

As per @JensEhrich's recommendation, I added another VM (macOS this time) and tried to connect from MacVM > WinVM. No luck, the connection could not be made. It looks like the firewall on WinVM is silently dropping the incoming packages.

I set up netcat on MacVM and tried to connect to it from both the host as well as the WinVM: both worked, even without port mapping set up for that guest (it seems that due to having a virtual NIC on the host that is part of the NAT, port mapping is only necessary for incoming traffic on the host's network, not on the host itself).

Thus, it seems that VMware NAT is not at fault, but WinVM is still blocking incoming connections, even though the firewall is completely disabled. But even after turning the firewall on, allowing incoming connections and then turning the firewall off again, the issue remained.

In the end it turned out the issue had nothing to do with VMware. In fact, to connect to guests from the host machine, no port mapping was necessary at all (as the host has a virtual network adapter that is part of the same virtual NAT).

The issue that prevented inbound traffic from reaching the guest VM, was the VPN client running on the guest, which tries to secure VPN endpoints by activating its own firewall and preventing any incoming network traffic.