VMware Communities: Message List - Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

Re: Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

JurgenD — Tue, 23 Dec 2008 20:33:44 GMT

yes, indeed. This behaviour seems to be changed at VMware Workstation 6.5
I could spoof the mac adress by modification of the vmx configuration file of the virtual machine,
and beyond the old limit of 00:50 etc.

I removed:

ethernet0.addressType = "generated"
ethernet0.generatedAddress = "00:0c:29:8d:b5:f5"
ethernet0.generatedAddressOffset = "0"

And appended:

ethernet0.addressType = "static"
ethernet0.address = "00:14:4F:28:5E:01"
ethernet0.noForgedSrcAddr = "FALSE"
ethernet0.checkMACAddress = "FALSE"
ethernet0.downWhenAddrMismatch = "FALSE"
ethernet0.noPromisc = "FALSE"

Et voila ! This works finally. Perfect. Thanks.

Re: Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

JurgenD — Mon, 15 Dec 2008 17:27:02 GMT

I do not agree. The RFC are not a law. They are recommendations.

There is nothing wrong to clone a MAC address on a virtual NIC from an internal hardware NIC.
The virtual NIC is not a hardware NIC, so it is not bound to the uniqueness of assigning MAC address.

Mac spoofing is well discussed into many topics.
In unix / linux / xxxBsd You can very easy do that with some settings to Your configuration.

As many routers, gateways, hardware firewall, repeaters or software do provide the ability to
clone a MAC from an internal host. So if some user decide to perform routing, packet filtering, intrusing detection
or even stress-security testing inside a virtual machine, he can not be excluded to do the same.

So You can discuss endless arround this matter. But my points stands.

It is a commercial disadvantage if You are excluded to make those changes, but You can with other opensource software. Of course, You
can force them to do the same as You have decided in Your policies. But this can be very easy made undone by changing the source and compiling the package by Your own.

And secondly, as said, a virtual machine does need, to 'emulate' as best as possible a real machine. So the user should and could choose,
which NIC he wants to emulate, including it's MAC address.

And if that's a violation, well, this is the responsibility of the user.
You can mention it in the EULA of Your software.

But I agree on this, those changes should and could only be done in the system-wide section,
so only a superuser can change them to protect an internal network from inside attacks.
The same superuser can decide to block communication to the public networks by firewall rules,
if he feels it is a violation of the RFC. I repeat, IF this is the case (which is NOT, in case of running routing software in a VM, etc).

Re: Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

jameslin — Tue, 09 Dec 2008 19:41:36 GMT

JurgenD wrote:
Some versions of VMware Workstation did allow to set manually the MAC address of the virtual adapter.
This possibility has changed for several reasons.

Hm? AFAIK we haven't added any restrictions. We don't provide a UI for it, but manually editing the .vmx file and changing ethernet0.addressType and ethernet0.address to a MAC address from a different vendor seems to work for me.

http://sanbarrow.com/vmx/vmx-network-advanced.html#mac

I don't believe static MAC addresses are actually limited to the 00:50:56 range.

Re: Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

RDPetruska — Tue, 09 Dec 2008 19:40:55 GMT

JurgenD wrote:Well, You could on some versions, with some hack and stuff.
But this is not important.

Important is, other virtualization software does allow to enter Your own MAC adress ! Without limits on the HEX numbers ( range, pool )

So this limit should be removed on the versions of VMware.
Maybe it is an advantage for some people, but not for those who need to perform MAC spoofing
or those who need to run and develop software, which does licensing based on a MAC address.

A vitual machine needs to be as compatible as possible.

If others are doing it, then they are in violation of Internic policies! VMware allows you to change the MAC addresses of their network adapters only within the range they were assigned by Internic. If other vendors allow you to change willy-nilly, then they are breaking the law!!

If you want to do spoofing, then do it inside the guest OS at that level (there are tools to allow you to do this for *nix and Windows environments, at least.

Re: Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

JurgenD — Tue, 09 Dec 2008 19:28:38 GMT

Well, You could on some versions, with some hack and stuff.
But this is not important.

Important is, other virtualization software does allow to enter Your own MAC adress ! Without limits on the HEX numbers ( range, pool )

So this limit should be removed on the versions of VMware.
Maybe it is an advantage for some people, but not for those who need to perform MAC spoofing
or those who need to run and develop software, which does licensing based on a MAC address.

A vitual machine needs to be as compatible as possible.

Re: Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

continuum — Tue, 09 Dec 2008 19:17:11 GMT

It never was possible to assign ANY MAC-address to a VM by editing the vmx-file.
You were always restricted to use an address out of a VMware-address pool.

Response of VMware is, You need to run the Server Edition. Well.....

I can't believe that ...

___________________________________

description of vmx-parameters: http://sanbarrow.com/vmx.html
VMware-liveCD: http://sanbarrow.com/moa.html

Old PITA - Change the MAC adress in VMware Workstation 6.5 ?!

JurgenD — Tue, 09 Dec 2008 19:10:01 GMT

Some versions of VMware Workstation did allow to set manually the MAC address of the virtual adapter.
This possibility has changed for several reasons.

My personal opinion is clear. A virtual machine needs to mirror as best as possible a hardware machine.

On VMware Workstation You can not change the MAC adress, or You are bound to a limited possibility, were the first hex adresses are fixed,
so it shows on the outside, it is a virtual machine. Response of VMware is, You need to run the Server Edition. Well.....

Currently I saw, the recent version of Virtual Box does allow to enter manually the MAC address
for the Virtual Interfaces based on Intel NIC. You can enter any MAC address, including MAC of existing, hardware Intel NIC.

So my opinion, the locked-out possibility to change FULLY the mac adress of the virtual machine,
should be enabled again for all versions of VMware, as it is the possibility with other software.