BladeSystem Management Software

HP OneView versus VCEM generated MAC and WWN - always different ?

Trusted Contributor

HP OneView versus VCEM generated MAC and WWN - always different ?

Theo had a question regarding management systems generating MAC addresses and WWNs for server profiles






Have a customer introducing HP OneView beside VCEM in the same datacenter but on different chassis c7000.

How can I be absolutely sure not to have duplicate  MAC and WWN range ?

Are Auto-generated the right ones ? Are they really different from VCEM range ?


My findings in the different documentations:


There are three alternatives for managing MAC and WWN information in HP OneView.


Which approach is best for your environment depends on whether you want to recreate HP OneView server profiles


with the identical MAC and WWN settings from your Virtual Connect environment,


or whether you want HP OneView to assign MACs and WWNs from either an auto-generated or a customer-defined pool of addresses.




There is a slight difference in the HP OneView algorithm for assigning WWPN and WWNN values from the Virtual Connect algorithm.


HP OneView allocates the WWPN as the value of the WWNN+1. Virtual Connect uses the reverse order, allocating the WWNN as the value of the WWPN+1.


You can also use factory-assigned MACs and WWNs in HP OneView just as you can in Virtual Connect.


HP OneView addressing

HP OneView pools address ranges just like VCEM does. However, HP OneView provides many more address ranges by using locally administered addresses, including auto-generated pools that can greatly expand the pool capacity. By default, there are approximately 1 million IDs in each MAC and WWN pool.

HP OneView administrators can also enter user-specified IDs when adding connections to server profiles.


Guys, is there a documentation stating that “OneView auto-generated MAC and WWN”

Will always be different from the VCEM generated ones ?

The customer wants to be sure absolutely when having both in the same datacenter .





Reply from Benjamin:




I already answer Theo’s question as he asked me directly but as it may help other people…


A MAC address is made of 6 bytes.

In the first byte, the 7th bit define if addresses are universally administered addresses or locally administered addresses.

VC and VCEM addresses are universally administered addresses (7th bit set to 0) and are associated to HP.

Addresses used in OneView are locally administered addresses (7th bit set to 1)


This makes VC/VCEM defined addresses different from OneView generated addresses.


There is the same mechanism for WWN.