Configuration Guide User guide

FastIron Configuration Guide 275
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Brocade IronStack management
rconsole-2@Brocade# exit
rconsole-2@Brocade> exit
Disconnected. Returning to local session...
Establish a remote console session with stack unit 3.
Brocade# rconsole 3
Connecting to unit 3... (Press Ctrl-O X to exit)
rconsole-3@Brocade# show stack
ID Type Role Mac Address Prio State Comment
3 S FCX624P member 001b.ed7a.22c0 0 local Ready
rconsole-3@Brocade# logout
Disconnected. Returning to local session...
Brocade#
IronStack management MAC address
The IronStack is identified in the network by a single MAC address, usually the MAC address of the
Active Controller (the default). If a new Active Controller is elected, the MAC address of the new
Active Controller (by default) becomes the MAC address for the entire stack. However, you can
manually configure your stack to use a specified MAC address. Refer to “Manually allocating the
IronStack MAC address” on page 275.
In an IronStack, the management MAC address is generated by the software, and is always the
MAC address of the first port of the Active Controller. This ensures that the management MAC
address remains consistent across stack reboots, and helps prevent frequent topology changes as
a result of protocol enable, disable, and configuration changes.
When you are configuring Layer 2 protocols on stack units, such as STP, RSTP, and MSTP, the
management MAC address of the Active Controller acts as the Bridge ID.
You can also configure the IronStack to retain its original MAC address, or wait for a specified
amount of time before assuming the address of a new Active Controller, using the Persistent MAC
Address feature (refer to “Persistent MAC address for the IronStack” on page 286).
Manually allocating the IronStack MAC address
You can manually configure your IronStack to use a specific MAC address. This overrides the
default condition where the stack uses the MAC address of whatever unit is currently serving as
Active Controller.
NOTE
The stack mac command is useful for administration purposes, however it should be used with
caution to prevent duplication of MAC addresses.
NOTE
For hitless stacking failover, Brocade recommends that you configure the IronStack MAC address
using the stack mac command. Without this configuration, the MAC address of the stack will change
to the new base MAC address of the Active Controller. This could cause a spanning tree root change.
Even without a spanning tree change, a client (for example, a personal computer) pinging the stack
might encounter a long delay depending on the client MAC aging time. The client won’t work until it
ages out the old MAC address and sends ARP requests to relearn the new stack MAC address.