Users Guide

252 Stacking
Default Stacking Values
Stacking is always enabled on Dell EMC Networking N-Series switches.
On the Dell EMC Networking N1100-ON/N1500/N4000 Series switches, by
default, the 10G SFP+ ports are in Ethernet mode and must be configured to
be used as stacking ports. Ports that are configured in stacking mode show as
“detached” in the output of the show interfaces status command.
Configuring an Ethernet port as a stacking port changes the default
configuration of the port. To determine the stacking configuration of a port,
use the show switch stack-ports command. On the Dell EMC Networking
N2000/N2100-ON/N3000 Series switches, there are two fixed stacking ports
in the rear of the switch. The N3100-ON supports a pluggable stacking
module in the rear. Stacking on Ethernet ports is not supported. The fixed
stacking ports show as TwentyGigabitStacking and are abbreviated Tw.
NSF is enabled by default. NSF can be disabled to redirect the CPU resources
consumed by data checkpointing; however, this is ill-advised, as
checkpointing consumes almost no switch resources. Checkpointing only
occurs when a backup unit is elected, so there is no need to disable the NSF
feature on a standalone switch. When a new unit is added to the stack, the
new unit is given the configuration of the stack, including the NSF setting.
OSPF implements a separate graceful restart control that enables NSF for
OSPF. OSPF graceful restart is not enabled by default.
NOTE: N1124T-ON/N1148T-ON/N1124P-ON/N1148P-ON/N1500 10G SFP+ ports
may only be configured as stacking in adjacent pairs, e.g. Te1/0/1 and Te1/0/2. If
configuring all four ports as stacking, the pairs of stacking links must be connected
to the same unit, i.e. both Te1/0/1-2 must connect to a single adjacent stack unit.