#Vmware mac address oui for mac
#Vmware mac address oui full

Registered virtual machines per vCenter Server: 35000 Locally administered addresses (LAA) – the alternative to VMware provided MAC addressesīefore we continue let’s revisit the the MAC address guidelines from IEEE (little did I know about this before this post). Powered-on virtual machines per vCenter Server: 25000 As an example the supported numbers for vCenter 6.7: Personally, I don’t think that is not an issue if you look at the scale limits listed in the VMware ConfigMax. The second thing people notice in the documentation is the limit of 64000 unique addresses per vCenter. On a side node: About the number of VMs and available MAC addresses Converting these number delivers us 80 hex = 123 dec and 43 dec = 2B hex which makes it a total of 123 decimal or AB in hex. Counterintuitively, the specified offset of 80 is a hex number and the shown vCenter ID 43 is a decimal. In my case, all my virtual machines get a MAC from the 00:50:56: AB:YY:ZZ range. The addresses created through the VMware OUI allocation are in the range 00:50:56:80:YY:ZZ – 00:50:56:BF:YY:ZZ. Taken from the same documentation page as before:Īccording to the VMware OUI allocation scheme, a MAC address has the format 00:50:56:XX:YY:ZZ where 00:50:56 represents the VMware OUI, XX is calculated as (80 + vCenter Server ID), and YY and ZZ are random two-digit hexadecimal numbers. A complete list of all OUI is available from the IEEE (see further down). The OUI covers 22 bits in a MAC address, in general identifying the vendor (it is actually a bit more complicated than that – but let’s leave it here for now). VMware Organizationally Unique Identifier (OUI) You can find the vCenter Server ID of your current installation in the general settings of the vCenter With the initial setup each vCenter gets a randomly generated ID that allows for 64 different values.

Let’s dig into this by starting with the vCenter Server ID. Source: VMware vSphere 6.7 documentation vCenter Server ID VMware Organizationally Unique Identifier (OUI) allocation assigns MAC addresses based on the default VMware OUI 00:50:56 and the vCenter Server ID.

#Vmware mac address oui for mac

The default behavior for MAC address assignment to virtual machines (or rather network adapters) in vSphere is very well documented and I think everyone has come to know the famous prefix: And even if you are one, think twice and in terms of effort versus gains first. If you have a high number of vCenters there is chance that you might end up with the same MAC addresses across different vCenter instances.īut the TL, DR: Don’t panic if you are not a big enterprise or service provider. As always please do your own research before you put this untested into production.

#Vmware mac address oui full

Given, it is somewhat of an edge case for only a hand full of customers and the problem itself is not new but here is my take. Recently another TAM requested some infos on this topic in VMware’s slack, finally giving me the push to publish as I had this post for ages in my drafts.