Cisco DS-C9216I-K9, Руководство по настройке

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31-5
Cisco MDS 9000 Fabric Manager Switch Configuration Guide
OL-7753-01
Chapter 31 Advanced Features and Concepts
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 supervisor module, assigns WWNs to each switch. This WWN is independent of other
WWNs on each switch. This centralized control of WWN has the following advantages:
•
Efficient sharing of WWN space
• Centralized support across switches
Cisco MDS 9000 Family switches support three network address authority (NAA) address formats.
Caution Changes to the worldwide names should be made by an administrator or individual who is completely
familiar with switch operations.
Allocating Flat FC IDs
Fibre Channel standards require a unique FC ID to be allocated to a N port attached to a Fx port in any
switch. To conserve the number of FC IDs used, Cisco MDS 9000 Family switches use a special
allocation scheme.
Based on the assigned FC ID, some HBAs assume that no other ports have the same area bits and domain.
When a target is assigned with a FC ID that has the same area bits, but different port bits, the HBA fails
to discover these targets. To isolate these HBAs in a separate area, switches in the Cisco MDS 9000
Family follow a different FC ID allocation scheme. By default, the FC ID allocation mode is
auto . In
the auto mode, only HBAs without interop issues are assigned FCIDs with specific ports bits. All other
HBAs are assigned FC IDs with a whole area (port bits set to 0).
The three options to allocate FCID are auto (default), none, and flat.
Caution
Changes to FC IDs should be made by an administrator or individual who is completely familiar with
switch operations.
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