Cisco Nexus 5000 Series Switch Fabric Manager Software Configuration Guide, NX-OS 4.0 (OL-16598-01, June 2008)

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22-5
Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
Chapter 22 Advanced Features and Concepts
World Wide Names
Note The number of pending fctimer configuration operations cannot be more than 15. After 15 operations,
you must commit or abort the pending configurations before performing any more operations.
See the “CFS Merge Support” section on page 7-6 for additional information.
World Wide Names
The world wide name (WWN) in the switch is equivalent to the Ethernet MAC address. As with the MAC
address, you must uniquely associate the WWN to a single device. The principal switch selection and
the allocation of domain IDs rely on the WWN.
Nexus 5000 Series switches support three network address authority (NAA) address formats
(see Table 22-1).
Caution Changes to the world-wide names should be made by an administrator or individual who is completely
familiar with switch operations.
This section includes the following topics:
• Verifying WWN Information, page 22-5
• Link Initialization WWN Usage, page 22-5
• Configuring a Secondary MAC Address, page 22-6
Verifying WWN Information
To display WWN information using Device Manager, choose FC > Advanced > WWN Manager. You
see the list of allocated WWNs.
Link Initialization WWN Usage
Exchange Link Protocol (ELP) and Exchange Fabric Protocol (EFP) use WWNs during link
initialization. ELPs and EFPs both use the VSAN WWN by default during link initialization. However,
the ELP usage changes based on the peer switch’s usage:
• If the peer switch ELP uses the switch WWN, then the local switch also uses the switch WWN.
• If the peer switch ELP uses the VSAN WWN, then the local switch also uses the VSAN WWN.
Table 22-1 Standardized NAA WWN Formats
NAA Address NAA Type WWN Format
IEEE 48-bit address Type 1 = 0001b 000 0000 0000b 48-bit MAC address
IEEE extended Type 2 = 0010b Locally assigned 48-bit MAC address
IEEE registered Type 5 = 0101b IEEE company ID: 24 bits VSID: 36 bits