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Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
OL-29284-01, Release 6.x
Chapter 3 Configuring Fibre Channel Interfaces
Information About Fibre Channel Interfaces
All ports in the 48-port and 24-port 4-Gbps modules can be configured to operate at 4 Gbps in shared
mode even if other ports in the port group are configured in dedicated mode, regardless of available
bandwidth. However, when oversubscription ratio restrictions are enabled, you may not have all shared
4-Gbps module ports operating at 4 Gbps.
All ports in the 48-port, 32-Port, and 24-port 8-Gbps modules can be configured to operate at 8 Gbps in
shared mode even if other ports in the port group are configured in dedicated mode, regardless of
available bandwidth. However, when oversubscription ratio restrictions are enabled you may not have
all shared 8-Gbps module ports operating at 8 Gbps.
On the 48-port, 32-Port, and 24-port 8-Gbps modules, if you have configured one 8-Gbps dedicated port
in one port group, no other ports in the same port group can be configured to operate at 8-Gbps dedicated
mode. You can have any number of 8-Gbps shared and 4-Gbps dedicated or shared ports. On the
4/44-port 8-Gbps module, only one port per port group can be configured in 8-Gbps dedicated or shared
mode.
In the following example, a 24-port 4-Gbps module has oversubscription ratios enabled and three
dedicated ports in one port group operating at 4-Gbps. No other ports in the same port group can be
configured to operate at 4 Gbps.
switch# show port-resources module 8
Module 8
Available dedicated buffers are 5478
Port-Group 1
Total bandwidth is 12.8 Gbps
Total shared bandwidth is 0.8 Gbps
Allocated dedicated bandwidth is 12.0 Gbps
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Interfaces in the Port-Group B2B Credit Bandwidth Rate Mode
Buffers (Gbps)
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Ta b l e 3-9 Bandwidth Allocation for Oversubscribed Interfaces
Switching
Module
Configured Speed
Reserved Bandwidth (Gbps) Maximum
Bandwidth
(Gbps)
Ratios enabled Ratios disabled
24-Port 8-Gbps
Fibre Channel
Module
Auto 8 Gbps 0.8 0.8 8
Auto Max 4 Gbps 0.4 0.4 4
Auto Max 2 Gbps 0.2 0.2 2
4/44-Port
8-Gbps
Host-Optimized
Fibre Channel
Module
8 Gbps 0.87 0.16 8
Auto Max 4 Gbps 0.436 0.08 4
Auto Max 2 Gbps 0.218 0.04 2
1 Gbps 0.109 0.02 1
48-port 4-Gbps
Fibre Channel
switching
module
Auto 4 Gbps 0.8 0.09 4
Auto Max 2 Gbps 0.4 0.045 2
1 Gbps 0.2 0.0225 1
24-port 4-Gbps
Fibre Channel
switching
module
Auto 4 Gbps 1 0.27 4
Auto Max 2 Gbps 0.5 0.135 2
1 Gbps 0.25 0.067 1
