Administrator Guide

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
4 Member online MXL-10/40GbE MXL-10/40GbE 9-1-0-853 56
5 Member online MXL-10/40GbE MXL-10/40GbE 9-1-0-853 56
Dell#
Failover Roles
If the stack master fails (for example, is powered o), it is removed from the stack topology.
The standby unit detects the loss of peering communication and takes ownership of the stack management, switching from the
standby role to the master role. 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 MXL switch 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 dierent unit becomes the stack master.
Stacking LAG
When multiple links are used between stack units, the Dell Networking OS automatically bundles them in a stacking LAG to provide
aggregated throughput and redundancy.
The stacking LAG is established automatically and transparently by the Dell Networking OS (without user conguration) 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.
Supported Stacking Topologies
Stacking is supported on the MXL switch in ring and daisy-chain topologies.
Example 1: Dual-Ring Stack Across Multiple Chassis
Using two separate stacks in a dual-ring stacking topology provides redundancy and increased high availability in case of stack failure.
Also, stacking upgrades are simplied when you have to take one stack oine, as shown in the following example.
Stacking
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