Administrator Guide

Stack Master Election
When a PE stack reloads and all stack units come up, all units participate in the stack master election. The master and standby units are
chosen based on the priority or MAC address. The stack takes the MAC address of the master unit.
• Unit priority — The range is from 1 to 14. The unit with the highest priority is elected the master management unit; the unit with the
second highest priority is elected the standby unit. The default is 0. To remove a priority and set the priority to 0, enter the no
stack-unit unit-number priority command in PE CONFIGURATION mode.
• MAC address (if there is a priority tie) — By default, the unit with the highest MAC value becomes the master unit if no priorities are
congured.
A change in the stack master occurs when:
• You power down the stack master.
• A failover of the master switch occurs.
• You disconnect the master switch from the stack.
NOTE: If a stack unit does not boot up at the same time as the other units, it does not participate in the election process. Units
that boot up late do not participate in the election process because the master and standby have already been elected. The unit
that boots up late (even if they have a higher priority congured) joins as a member.
To display the PE stack master, enter the show pe pe—id system brief command.
The following example shows output from an established stack.
Example of Displaying Stack Members
Dell#show pe 0 system brief
Stack MAC: a0:68:00:3f:92:bc
-- Stack Info --
Unit UnitType Status ReqTyp CurTyp Version Ports
---------------------------------------------------------------------------
0 Management online C1048P C1048P 1-0(0-4879) 52
1 Member online C1048P C1048P 1-0(0-4879) 52
2 Standby online C1048P C1048P 1-0(0-4879) 52
3 Member online C1048P C1048P 1-0(0-4879) 52
4 Member online C1048P C1048P 1-0(0-4879) 52
5 Member online C1048P C1048P 1-0(0-4879) 52
6 Member online C1048P C1048P 1-0(0-4879) 52
7 Member online C1048P C1048P 1-0(0-4879) 52
Important Points to Remember
• You can stack up to eight port extenders.
• You cannot stack C1048P port extenders with other system types.
• You can stack N20xx series devices with only N20xx series devices.
• You can stack N30xx series devices with only N30xx series devices.
• Set up a PE stack by using the dedicated stacking ports on the back panel. Dell Networking recommends using a ring topology for a PE
stack.
• All stack units must have the same version of Dell Networking OS.
• When you restore the factory-default settings on all units in a stack, the units are placed in standalone mode.
• Dell Networking recommends connecting more than one PE stack unit to the C9010 for redundancy. (Individual PE stack members do
not require a separate uplink to a parent C9010 because they use the stacking connection to the master PE for their C9010 uplink.)
Port Extender (PE) Stacking
759