`system-mac`

Syntax

system-mac <MAC-ADDR>

no system-mac <MAC-ADDR>

Description

Sets the MAC address as the VSX system MAC address to be used by control plane protocols, such as STP and LACP. A pair of VSX switches must have the same VSX system MAC.

The no form of this command unconfigures the VSX system MAC address to be used by control plane protocols.

Command context

config-vsx

Parameters

<MAC-ADDR>: Specifies the MAC address in a colon separated format, such as XX:XX:XX:XX:XX:XX, for control plane protocols.

Authority

Administrators

Usage

The

system-mac 
			 <MAC-ADDR>

command is highly recommended for preventing traffic disruptions when the primary VSX switch restores after the secondary VSX switch, such as during:

a primary switch hardware replacement.
A power outage with the primary switch restore after the secondary switch restore.

When the primary switch is restored after the secondary switch, a traffic disruption might occur when the ISL starts to sync. This situation occurs because the MAC system address changes from the secondary switch to the primary switch for the LACP. To avoid the traffic disruption, set the common system MAC address by entering the system-mac <MAC-ADDR> command. This command creates a common system MAC address between the two VSX switches. This common system MAC address prevents a traffic disruption when the secondary switch comes up before the primary switch. If the common system MAC access is enabled, the secondary switch uses the common system MAC address instead of its own system MAC address, which prevents a traffic loss.

The system MAC address also maintains the same MSTP bridge ID across VSX switches, which act as a single switch.

Examples

Setting a MAC address as the VSX system MAC address to be used by control plane protocols:

switch(config-vsx)# system-mac 00:00:00:02:02:02

Unconfiguring a VSX system MAC address to be used by control plane protocols:

switch(config-vsx)# no system-mac 00:00:00:02:02:02