Type storage:WWN

The first character of the WWN is the Network Address Authority value. It indicates the format of the WWN itself. The possible values are:
1 - IEEE 803.2 standard 48 bit ID
2 - IEEE 803.2 extended 48-bit ID
5 - IEEE Registered Name
6 - IEEE Extended Registered Name

All devices on a storage area network MUST be uniquely identifiable. This is to ensure that data transmission occurs between the correct source and target device across the SAN fabric.
In order to guarantee the uniqueness of node and port WWNs assigned to Service Profiles, you are STRONGLY encouraged to use the following WWN range for node WWNs and HBA WWNs assigned to Service Profiles:
20:00:00:25:b5:hh:hh:hh
This range has been registered as a vendor-specific OUI for the UCS system and allows you to create 16,777,215 unique WWN values. Selecting WWN values outside the 20:00:00:25:b5:hh:hh:hh range could result in duplicate WWN values in the SAN fabric.
You should carefully evaluate situations when you select a WWN range outside 20:00:00:25:b5:hh:hh:hh. A possible use case could be when a SAN array is already configured and a set of servers are decommissionned and then replaced by UCS servers.

When the first character is set to "2", the format is divided into 4 sections:

1. The first character ("2") indicates it is a IEEE 803.2 extended 48-bit ID
2. The next 3 characters are a vendor specific code and can be used to identify specific ports on a node or to extend the serial number (section 4) of the WWN.
3. The next 6 characters identify the vendor.
4. The last 6 characters are a unique vendor-supplied serial number for the device.