HP Surestore 6164 - Switch Reference Manual page 111

Fibre Alliance MIB Object Types
The following characteristics are strongly recommended:
When a nonzero value is provided, it should be persistent across agent and
unit resets.
• This value should be globally unique.
• This value should be one of these FC-PH/PH3 formats:
– IEEE (NAA=1)
– IEEE Extended (NAA=2)
– IEEE Registered (NAA=5)
– IEEE Registered extended (NAA=6)
Use of the IEEE formats allows any IEEE-registered vendor to assure
global uniqueness independently.
The following are some references on IEEE WWN formats:
http://standards.ieee.org/regauth/oui/tutorials/fibreformat.html
http://standards.ieee.org/regauth/oui/tutorials/fibrecomp_id.html
If one or more WWNs are associated with the connUnit using other
management methods, one of the WWNs should be used for
connUnitGlobalId.
If there is not a WWN assigned specifically to the connUnit, there is some
merit, though not a requirement, to using a WWN assigned to one of its
permanently attached FC/LAN interfaces. However this WWN must not be
unique.
As a counter example, if your agent runs in a host and the host has an HBA,
the agent, host, and HBA can be distinct connUnits, so the host and agent
cannot use the WWN of the HBA.
Another example:
If your hub has a built-in Ethernet port, the hub can use its LAN address
(prefixed with the appropriate NAA) as its connUnitId. But if the Ethernet
were a replaceable PC Card, the hub should have an independent ID.
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