Concept Guide
Mixed-mode Stacking
Mixed-mode stacking enables you to stack one or more S4048-ON switches with the S4048T-ON switches and vice versa.
If mixed-mode stacking is not enabled, a S4048-ON switch cannot join a S4048T-ON stack or a stack that contains a mix of both the
S4048-ON as well as the S4048T-ON switches. However, the S4048-ON switches can join a S4048-ON stack without having to enable
mixed-mode stacking.
Similarly, if mixed-mode stacking is not enabled, a S4048T-ON switch cannot join a S4048-ON stack or a stack that contains a mix of both
the S4048T-ON as well as the S4048-ON switches. However, the S4048T-ON switches can join a S4048T-ON stack without having to
enable mixed-mode stacking.
NOTE: Even though the S4048-ON and S4048T-ON belong to the same family of switches, the system detects a card-type
mismatch during stack insertion if mixed-mode stacking is not enabled.
When a S4048T-ON switch, on which mixed-mode stacking is enabled, joins a S4048-ON stack, the S4048T-ON switch is rebooted. The
hardware tables of the S4048T-ON are re-initialized in order to make the table sizes of the S4048T-ON identical to the S4048-ON
switches. In this scenario, the S4048-ON congurations are pushed to the newly joined S4048T-ON and the switch successfully joins the
stack. However, if mixed-mode stacking is disabled on the S4048T-ON, the system detects a card-type mismatch and moves the S4048T-
ON into a card problem state.
When a S4048T-ON switch, on which mixed-mode stacking is enabled, joins a stack that contains both S4048-ON as well as S4048T-ON
switches, the new S4048T-ON switch is rebooted. The hardware tables of the S4048T-ON switch are re-initialized in order to make the
table sizes identical to the S4048-ON switches. In this scenario, the S4048-ON congurations are pushed to the newly joined S4048T-ON
and the switch successfully joins the stack. However, if mixed-mode stacking is disabled on the S4048T-ON switch, the system detects a
card-type mismatch and the S4048T-ON switch remains in a card problem state.
When a S4048-ON switch, on which mixed-mode stacking is enabled, joins a stack with S4048T-ON as the master, the entire stack is
rebooted. The hardware tables of the existing S4048T-ON units are re-initialized in order to make their table sizes identical to the S4048-
ON switches. In this scenario, as mixed-mode stacking is enabled, the system will not detect a card-type mismatch. The S4048-ON switch
successfully joins the S4048T-ON stack. However, if mixed-mode stacking is not enabled on the S4048-ON switch, the system detects a
card-type mismatch and the S4048-ON switch remains in a card problem state.
When a S4048-ON switch, on which mixed-mode stacking is enabled, joins a stack that contains both S4048-ON as well as S4048T-ON
switches, the new S4048-ON switch is accepted as a member unit. In this scenario, the newly joined S4048-ON switch or the stack will
not reboot as the hardware table sizes of both these platforms are already in sync.
NOTE
: Mixed-mode stacking enables stacking to form only between the S4048-ON and S4048T-ON switches. Any other variant
of the S-series switches are not allowed to join the stack that contains the S4048-ON and S4048T-ON switches. Even if mixed-
mode stacking is enabled on any switch other than the S4048-ON or S4048T-ON switches, the new unit is not allowed to join a
stack that contains S4048-ON or S4048T-ON switches.
Important Points on Mixed-mode Stacking
• To form a mixed-mode stack, use only the 40G ports between the range 49 to 54.
• You cannot form a mixed-mode stack using the 10G ports. Because, the 10G ports on the S4048T-ON are copper ports; where as, the
10G ports on the S4048-ON are SFP ports.
• It is mandatory to enable mixed-mode stacking on the S4048-ON and S4048T-ON switches before joining a mixed-mode stack.
• Stack election is based on the priority or the MAC address of the stack units as in homogenous stacking. The stack-unit with the
highest priority or MAC address is chosen as the master.
986
Stacking