Cisco Nexus 5000 Series Switch CLI Software Configuration Guide, NX-OS 4.0(1a)N1 (OL-16597-01, January 2009)

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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
OL-16597-01
Chapter 33 Configuring Domain Parameters
Information About Fibre Channel Domains
When fast restart is enabled and a backup link is available, the domain manager needs only a few
milliseconds to select a new principal link to replace the one that failed. Also, the reconfiguration
required to select the new principal link only affects the two switches that are directly attached to the
failed link, not the entire VSAN. When a backup link is not available, the domain manager reverts to the
default behavior and starts a BF phase, followed by a principal switch selection phase. The fast restart
feature can be used in any interoperability mode.
Enabling Domain Manager Fast Restart
To enable the domain manager fast restart feature, perform this task:
About Switch Priority
By default, the configured priority is 128. The valid range to set the priority is between 1 and 254.
Priority 1 has the highest priority. Value 255 is accepted from other switches, but cannot be locally
configured.
Any new switch cannot become the principal switch when it joins a stable fabric. During the principal
switch selection phase, the switch with the highest priority becomes the principal switch. If two switches
have the same configured priority, the switch with the lower world-wide name (WWN) becomes the
principal switch.
The priority configuration is applied to runtime when the fcdomain is restarted (see the About Domain
Restart” section on page 33-3). This configuration is applicable to both disruptive and nondisruptive
restarts.
Configuring Switch Priority
To configure the priority for the principal switch, perform this task:
Command Purpose
Step 1
switch# configuration terminal
switch(config)#
Enters configuration mode.
Step 2
switch(config)# fcdomain optimize fast-restart
vsan vsan-id
Enables domain manager fast restart in the
specified VSAN.
switch(config)# fcdomain optimize fast-restart
vsan vsan-id - vsan-id
Enables domain manager fast restart in the
specified range of VSANs.
switch(config)# no fcdomain optimize
fast-restart vsan vsan-id
Disables (default) domain manager fast restart
in the specified VSAN.
Command Purpose
Step 1
switch# configuration terminal
switch(config)#
Enters configuration mode.
Step 2
switch(config)# fcdomain priority number VSAN
vsan-id
Configures the specified priority for the local
switch in the specified VSAN.
switch(config)# no fcdomain priority number
VSAN vsan-id
Reverts the priority to the factory default (128)
in the specified VSAN.