Cisco Catalyst 3750-X Command Reference

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Catalyst 3750-X and 3560-X Switch Command Reference
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Chapter 2 Catalyst 3750-X and 3560-X Switch Cisco IOS Commands
stack-mac persistent timer
stack-mac persistent timer
Use the stack-mac persistent timer global configuration command on the switch stack or on a standalone
switch to enable the persistent MAC address feature. When this feature is enabled, if the stack master
changes, the stack MAC address does not change for approximately four minutes, for an indefinite time
period, or for a configured time value. If the switch that was previously the stack master rejoins the stack
during this period, the stack continues to use its MAC address as the stack MAC address, even if the
switch is now a stack member. Use the no form of this command to return to the default setting.
stack-mac persistent timer [0 | time-value]
no stack-mac persistent timer
Note This command is supported only on Catalyst 3750-X switches.
Syntax Description
Defaults Persistent MAC address is disabled. The MAC address of the stack is always that of the stack master.
When the command is entered with no value, the default time before the MAC address changes is
4 minutes. We recommend that you configure an explicit value for this command.
Command Modes Global configuration
Command History
Usage Guidelines The MAC address of the switch stack is determined by the MAC address of the stack master. In the
default state (persistent MAC address disabled), if a new switch becomes stack master, the stack MAC
address changes to the MAC address of the new stack master.
When persistent MAC address is enabled, the stack MAC address does not change for approximately
four minutes. During that time, if the previous stack master rejoins the stack as a stack member, the stack
retains its MAC address for as long as the switch that has that MAC address is in the stack. If the previous
stack master does not rejoin the stack, the switch stack takes the MAC address of the new stack master
as the stack MAC address.
If the whole stack reloads, when it comes back up, the MAC address of the stack master is the stack MAC
address.
0 (Optional) Enter to continue using the MAC address of the current stack master
after a new stack master takes over.
time-value (Optional) Set the time period in minutes before the stack MAC address
changes to that of the new stack master. The range is 1 to 60 minutes. When no
value is entered, the default is 4 minutes. We recommend that you configure an
explicit value for this command.
Release Modification
12.2(53)SE2 This command was introduced.

Cisco Catalyst 3750-X Specifications

General

Switching Capacity	160 Gbps
Stacking Bandwidth	64 Gbps
Max Stacking Units	9
Layer Support	Layer 2 and Layer 3
Form Factor	Rack-mountable
DRAM	256 MB
Flash Memory	64 MB
Model	Cisco Catalyst 3750-X Series
Ports	24 or 48 10/100/1000 Ethernet ports
Uplink Interfaces	4 SFP or 2 SFP+
Features	StackWise Plus, EnergyWise
Image	IP Base or IP Services
Operating Temperature	0 to 40°C
Operating Humidity	10 to 85% noncondensing