Configuration manual

from standby to master. The lack of a standby unit triggers an election within the remaining units for a
standby role.
After the former master switch recovers, despite having a higher priority or MAC address, it does not
recover its master role but instead takes the next available role.
MAC Addressing
All port interfaces in the stack use the MAC address of the management interface on the master switch.
The MAC address of the chassis in which the master Aggregator is installed is used as the stack MAC
address.
The stack continues to use the master’s chassis MAC address even after a failover. The MAC address is
not refreshed until the stack is reloaded and a different unit becomes the stack master.
Stacking LAG
When you use multiple links between stack units, Dell Networking Operating System automatically
bundles them in a stacking link aggregation group (LAG) to provide aggregated throughput and
redundancy. The stacking LAG is established automatically and transparently by operating system
(without user configuration) after peering is detected and behaves as follows:
• The stacking LAG dynamically aggregates; it can lose link members or gain new links.
• Shortest path selection inside the stack: if multiple paths exist between two units in the stack, the
shortest path is used.
Stacking VLANs
When you configure an Aggregator to operate in stacking mode (Configuring and Bringing Up a Stack),
VLANs are reconfigured as follows:
• If an Aggregator port belonged to all 4094 VLANs in standalone mode (default), all VLAN membership
is removed and the port is assigned only to default VLAN 1. You must configure additional VLAN
membership as necessary.
• If you had manually configured an Aggregator port to belong to one or more VLANs (non-default) in
standalone mode, the VLAN configuration is retained in stacking mode only on the master switch.
When you reconfigure an Aggregator from stacking to standalone mode:
• Aggregator ports that you manually configured for VLAN membership in stacking mode retain their
VLAN configuration in standalone mode.
• To restore the default auto-VLAN mode of operation (in which all ports are members of all 4094
VLANs) on a port, enter the auto vlan command; for example:
Dell(conf)# interface tengigabitethernet 0/2
Dell(conf-if-te-0/2)# auto vlan
Stacking
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