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

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Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
Chapter 31 Troubleshooting Your Fabric
Configuring World Wide Names
Configuring 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. The WWN manager, a process-level manager residing
on the switch’s supervisor module, assigns WWNs to each switch.
Cisco Nexus 5000 Series switches support three network address authority (NAA) address formats (see
Table 31-1).
Caution Changes to the world-wide names should be made by an administrator or individual who is completely
familiar with switch operations.
Link Initialization WWN Usage
Exchange Link Protocol (ELP) and Exchange Fabric Protocol (EFP) use WWNs during link
initialization. The usage details differ based on the Cisco SAN-OS software release:
Both ELPs and EFPs 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.
Configuring a Secondary MAC Address
To allocate a secondary MAC address, perform this task:
Step 1 Select a SAN (or a VSAN) from the Logical Domains pane.
You see a list of switches in the Information pane.
Step 2 Expand Switches, expand FC Services, and choose WWN Manager in the Physical Attributes pane.
Step 3 In the Information pane, scroll until you see the switch on which you want to configure a secondary MAC
address (see Figure 31-15).
Table 31-1 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