Reference Guide

• Shortest path selection inside the stack: If multiple paths exist between two units in the stack, the shortest path
is used.
Supported Stacking Topologies
The S4820T supports stacking in a ring or a daisy chain topology.
Dell Networking recommends the ring topology when stacking S4820T switches to provide redundant connectivity.
Figure 118. S4820T Supported Stacking Topologies
High Availability on S-Series Stacks
S-Series stacks have master and standby management units analogous to Dell Networking route processor modules
(RPM).
The master unit synchronizes the running configuration and protocol states so that the system fails over in the event of a
hardware or software fault on the master unit. In such an event, or when the master unit is removed, the standby unit
becomes the stack manager and FTOS elects a new standby unit. FTOS resets the failed master unit: after online, it
becomes a member unit; the remaining members remain online.
Example of S-Series Stack Manager Redundancy (S50)
Stack#show redundancy
-- Stack-unit Status --
------------------------------------------------
Mgmt ID: 0
Stack-unit ID:
1
Stack-unit Redundancy Role: Primary
Stack-unit State: Active
Stack-unit SW Version: 7.8.1.0
767