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

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22-8
Nexus 5000 Series Switch Fabric Manager Software Configuration Guide
OL-16598-01
Chapter 22 Advanced Features and Concepts
Switch Interoperability
Not all vendors follow the standards in the same way, which results in the need for interoperability
modes. This section briefly explains the basic concepts of these modes.
Each vendor has a regular mode and an equivalent interoperability mode, which specifically turns off
advanced or proprietary features and provides the product with a standards-compliant implementation.
This section includes the following topics:
• About Interop Mode, page 22-8
• Configuring Interop Mode 1, page 22-9
• Verifying Interoperating Status, page 22-11
About Interop Mode
Cisco NX-OS software supports the following four interop modes:
• Mode 1— Standards-based interop mode that requires all other vendors in the fabric to be in interop
mode.
• Mode 2—Brocade native mode (Core PID 0).
• Mode 3—Brocade native mode (Core PID 1).
• Mode 4—McData native mode.
For information about configuring interop modes 2, 3, and 4, see the Cisco MDS 9000 Family
Switch-to-Switch Interoperability Configuration Guide.
Table 22-2 lists the changes in switch operation when you enable interoperability mode. These changes
are specific to Nexus 5000 Series switches while in interop mode.
Table 22-2 Changes in Switch Operation When Interoperability Is Enabled
Switch Feature Changes if Interoperability Is Enabled
Domain IDs Some vendors cannot use the full range of 239 domains within a fabric.
Domain IDs are restricted to the range 97 to 127, to accommodate McData’s
nominal restriction to this same range. Domain IDs can either be static or
preferred, which operate as follows:
• Static: Cisco switches accept only one domain ID; if a switch does not get
that domain ID it isolates itself from the fabric.
• Preferred: If the switch does not get its requested domain ID, it accepts any
assigned domain ID.
Timers All Fibre Channel timers must be the same on all switches as these values are
exchanged by E ports when establishing an ISL. The timers are F_S_TOV,
D_S_TOV, E_D_TOV, and R_A_TOV.
F_S_TOV Verify that the Fabric Stability Time Out Value timers match exactly.
D_S_TOV Verify that the Distributed Services Time Out Value timers match exactly.
E_D_TOV Verify that the Error Detect Time Out Value timers match exactly.
R_A_TOV Verify that the Resource Allocation Time Out Value timers match exactly.
Trunking Trunking is not supported between two different vendor’s switches. This
feature may be disabled on a per port or per switch basis.