• Switch removal
If the master switch goes off line, the standby replaces it as the new master and the switch with the next
highest priority or MAC address becomes standby.
NOTE: For the MXL switch, the entire stack has only one management IP address.
Stack Master Election
The stack elects a master and standby unit at bootup time based on two criteria.
• Unit priority — User-configurable. The range is from 1 to 14. A higher value (14) means a higher
priority. The default is 0. To remove the stack-unit priority and set the priority back to the default
value of zero, use the no stack-unit priority command.
• MAC address (in case of priority tie) — The unit with the higher MAC value becomes the master unit.
To view which switch is the stack master, enter the show system command. The following example
shows sample output from an established stack.
A change in the stack master occurs when:
• You power down the stack master or bring the master switch offline.
• A failover of the master switch occurs.
• You disconnect the master switch from the stack.
When a stack reloads and all the units come up at the same time; for example, when all units boot up
from flash, all units participate in the election and the master and standby are chosen based on the
priority or MAC address.
When the units do not boot up at the same time, such as when some units are powered down just after
reloading and powered up later to join the stack, they do not participate in the election process even
though the units that boot up late may have a higher priority configured. This happens because the
master and standby have already been elected, hence the unit that boots up late joins only as a member.
When an up and running standalone unit or stack is merged with another stack, based on election, the
losing stack reloads and the master unit of the winning stack becomes the master of the merged stack.
For more details, see sections Adding a Stack Unit and Merging Two Stacks. To ensure a fully
synchronised bootup, it is possible to reset individual units to force them to give up the management
role; or reload the whole stack from the command line interface (CLI).
Example of Viewing Stack Members
Dell# show system brief
Stack MAC : 00:1e:c9:f1:00:7b
Reload Type : jump-start [Next boot : normal-reload]
-- Stack Info --
Unit UnitType Status ReqTyp CurTyp Version Ports
--------------------------------------------------------------------
0 Management online MXL-10/40GbE MXL-10/40GbE 9-1-0-853 56
1 Standby online MXL-10/40GbE MXL-10/40GbE 9-1-0-853 56
2 Member online MXL-10/40GbE MXL-10/40GbE 9-1-0-853 56
3 Member online MXL-10/40GbE MXL-10/40GbE 9-1-0-853 56
884
Stacking
