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thebigO
Contributor
Contributor

Virtual Machine Manual MAC Address Question

Just need some guidance here as I have to install an app on a VM and it requires a static MAC address.

I know how to do this on the VM and see it pre populate the first 3 octets but need some guidance on the last 3.

Is there a method or place in vCenter to generate or obtain a MAC to use or do I use an online MAC generator.

Doco on VMware is a bit vague on this.

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JarryG
Expert
Expert

AFAIK, MAC-address is always static. And concerning  values, the only thing you really have to take care of is there are not two (or more) network-adapters with the same mac-address on the same network-segment...

_____________________________________________ If you found my answer useful please do *not* mark it as "correct" or "helpful". It is hard to pretend being noob with all those points! 😉
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schepp
Leadership
Leadership

Hi,

when you keep the default settings, the MAC is set to automatic and is generated.

No need to change this. The MACs generated are quite static. They stay the same, even after power off/on / vMotion / SvMotion etc.

Regards

Tim

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thebigO
Contributor
Contributor

As an update I ended up calling a one of the Engineers from VMware to get an idea what they would say.  Engineer said he has never had to do this and as you said once it is generated and applied to a machine automatically there is no real reason it will change.

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Borja_Mari
Virtuoso
Virtuoso

Hello,

take a look to this, to gain knowledge about Mac address in vSphere.

Best regards,

Pablo

------------------------------------------------------------------------------------------------- PLEASE CONSIDER AWARDING any HELPFUL or CORRECT reply. Thanks!! Por favor CONSIDERA PREMIAR cualquier respuesta ÚTIL o CORRECTA . ¡¡Muchas gracias!! VCP3, VCP4, VCP5-DCV (VCP550), vExpert 2010, 2014 BLOG: http://communities.vmware.com/blogs/VirtuallyAnITNoob
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Wh33ly
Hot Shot
Hot Shot

Did it a few times, this article helped me do it

VMware KB: Changing the MAC address of a hosted virtual machine

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Borja_Mari
Virtuoso
Virtuoso

Hello,

take a look to this to gain knowledge about when vmware changes the virtual machines' mac address.

Best regards,

Pablo

------------------------------------------------------------------------------------------------- PLEASE CONSIDER AWARDING any HELPFUL or CORRECT reply. Thanks!! Por favor CONSIDERA PREMIAR cualquier respuesta ÚTIL o CORRECTA . ¡¡Muchas gracias!! VCP3, VCP4, VCP5-DCV (VCP550), vExpert 2010, 2014 BLOG: http://communities.vmware.com/blogs/VirtuallyAnITNoob
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CedricAnto
VMware Employee
VMware Employee

If you are looking to setup & draw from an automated pool to draw the MAC address for VM's, this is not user configurable/available.

This is internally maintained and provisioned when network adapters are added to VM's. This is not guaranteed from changing. in a multi- vCenter environment there could be duplicate MAC in the environment. These are based on arbitrary algorithm that vcenter uses based on an instance ID.

If your application is sensitive to MAC address remaining the same in the lifecycle of the VM, (sometime is the case with legacy app licensing tied to hardware)

Set it manually to static.

To do this, follow the document

vSphere 5.5 Documentation Center

KB article

VMware KB: Setting a static MAC address for a virtual NIC

Abstract

=====

Add these two lines to the virtual machine's configuration file:

ethernet0.addressType = "static"
ethernet0.address = 00:50:56:XX:YY:ZZ


Where XX is a valid hex number between 00 and 3F and YY and ZZ are valid hex numbers between 00 and FF. The value for XX must not be greater than 3F in order to avoid conflict with MAC addresses that are generated by the VMware Workstation and VMware GSX Server products. Thus the maximum value for a manually generated MAC address is:

ethernet0.address = 00:50:56:3F:FF:FF


VMware ESX Server virtual machines do not support arbitrary MAC addresses, hence the above format must be used. As long as you choose a hex value that is unique among your hard-coded addresses, conflicts between the automatically assigned MAC addresses and the manually assigned ones should never occur.

=====



Let me know if this addresses your question. Or please share a more detailed requirement/use case.





Cedric http://in.linkedin.com/in/cedricrajendran/ http://virtualknightz.com/
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