If you want to change the NAT network that VMware Player uses (by default
it is 192.168.5.0/24) then there are a few tasks to do. It's not
straightforward and for VMware Player, some of the steps are not well
documented.
NAT and DHCP should work out of the box
with VMware Player, no configuration necessary. However, there may come a
time that you need to change the network; there are a few good reasons
and if you're reading this then you know at least one of them.
When you hunt around on the internet for answers on
this, most of the responses are to just configure bridging. Actually in a
corporate environment, bridging may not make your network admins happy,
or actually fail, depending on how tightly controlled the network is.
Bridging is just like adding another host onto the network. NAT hides
the VM behind the VMware Host.
The following changes worked for me on
Windows 7 with VMware Player 7.1.0.
I'm not going into detail on the exact syntax of the config files
because if you don't understand subnets and the concept of interface
binding then this howto is not for you.
Set Up the Interface
On your host cd to install dir (C:\Program Files (x86)\VMware\VMware Player) and run the following commands.
Alternatively, you can change adapter and services through the normal networking services control panels.
The
instructions rely on vmnet8 being the adapter for NAT. By default, VM
Player installs two adapters, vmnet1 for the "Host-only" interface type
and vmnet8 for the "NAT" interface type.
On Windows 7 and 10 at least, the vnetlib commands have to be run with elevated privileges.
vnetlib.exe -- stop nat
vnetlib.exe -- stop dhcp
vnetlib.exe -- set vnet vmnet8 mask 255.255.255.0
vnetlib.exe -- set adapter vmnet8 addr 192.168.207.1
vnetlib.exe -- update dhcp vmnet8
vnetlib.exe -- update nat vmnet8
vnetlib.exe -- update adapter vmnet8
vnetlib.exe -- start dhcp
vnetlib.exe -- start nat
Note: These changes may lead to your config files (mentioned later) being re-written.
Configure DHCP and NAT
Note
that even if you intend to only use NAT with no DHCP, you must update
the DHCP settings to match the new interface subnet range. I found that
if there is something incorrect in either the NAT or DHCP config file,
the config files reverted to the defaults. I am not exactly sure what
sequence lead to that that, but I do know that it was as a result of
having mismatched subnets in the configs.
On VMware
Player, there appears to be no GUI for configuring the DHCP or NAT
services. VMware Workstation does seem to have a GUI.
Edit these files instead:
C:\ProgramData\VMware\vmnetdhcp.conf
C:\ProgramData\VMware\vmnetnat.conf
In
the NAT file, don't mess with the vmnet1 settings unless you intend to
change the Host-only interface type. I've actually disabled vmnat1 via
the Windows Control Panel; you don't need vmnet1 in my experience.
Then restart DHCP and NAT via the method above, or go to the services panel in windows and do it there.
The MAC that your VM will connect to is found here:
C:\ProgramData\VMware\vmnetnat-mac.txt
Verification
Now you should be able to reach what we call
in the industry "the internet", as long as you have routing and DNS set
up properly on your Host and VM.
You
can use Wireshark to capture on vmnet8 and check that packets from your
VM to the Host are using the destination MAC specified in
vmnetnat-mac.txt. Check that your VM has resolved the .2 address to this
MAC and that this is the default route.
There is a hostMAC stanza
in the vmnetnat.conf file that is actually telling the NAT service what
the interface MAC of the NAT vmnet device is. That MAC is actually
ignored by NAT. hostMAC seems to be there so that your Host to VM communication
(ssh, https etc) is excluded from NAT. You will see this in the event
log:
Using configuration file: C:\ProgramData\VMware\vmnetnat.conf.
IP address: 192.168.207.2
Subnet: 255.255.255.0
External IP address: 0.0.0.0
Device: vmnet8.
MAC address: 00:50:56:F1:77:9F.
Ignoring host MAC address: 00:50:56:C0:00:08.
The "MAC address" above is what your VM uses as the gateway:
# arp -an
? (192.168.207.2) at 00:50:56:f1:77:9f [ether] on eth0
|
In other words, the IP .1 is for host to VM communication and .2 is for NAT traffic.
VMNetDHCP Errors in Event Viewer
No
subnet declaration for VMnet8 (192.168.207.2). Please write a subnet
declaration for the network segment to which interface VMnet8 is
attached.
The network interface vmnet8 is in a different subnet to what you've configured in the DHCP config file.
Address range 192.168.178.128 to 192.168.207.254, netmask 255.255.255.0 spans multiple subnets!
You've written something pretty odd in the DHCP config file.
Important! Errors can lead to your config files being re-written.
VMware Player 7.1.4 Upgrade
After an install VMware Player 7.1.4 I could no longer connect from my workstation to the machines in the VM network.
Note that something weird is up with this install, after the install process WMware Player insists that the version is 6.0.7 build-2844087, yet when I run the "Help -> Software Updates" process it declares that my version is up to date (7.1.4 is the latest).
The workstation's VMnet8 adapter was statically set by the vnetlib.exe command earlier. But it is also specified in vmnetdhcp.conf. Although the adapter had a static address, it appeared to be using a "169.254.0.0" address, which generally indicates a failure to pick up a DHCP address.
Switching the adapter setting back to DHCP immediately picked up the address defined in vmnetdhcp.conf, namely:
host VMnet8 {
hardware ethernet 00:50:56:C0:00:08;
fixed-address 192.168.207.1;
option domain-name-servers 0.0.0.0;
option domain-name "";
option routers 0.0.0.0;
}
