Installation Guide

A single stack can use both native stacking ports and alternate stacking ports. On one switch, for
example, you can use a native stacking port to connect to a switch in the same rack, and you can use an
alternate stacking port to connect to a switch on a dierent floor.
Note
When you connect distant nodes using alternate stacking ports, be sure to run the cables over
physically dierent pathways to reduce the likelihood of a cut aecting multiple links.
On each switch model, only specific data ports can be used as alternate stacking ports. The alternate
stacking ports must be 10-Gbps Ethernet ports, either on the front panel of the switch or on installed
port option cards or versatile interface modules at the rear of the switch. Switch models that do not
have native stacking ports can still use alternate stacking if they have 10-Gbps Ethernet ports.
Alternate stacking ports on dierent switches must be directly connected, with no intervening switch
connections. This is because alternate stacking ports use the proprietary ExtremeXOS stacking protocol,
not the standard Ethernet protocol.
Table 114 lists the data ports that can be used as native and alternate stacking ports for each switch
model.
When the stacking-support option is enabled (with the enable stacking-support command),
data communication stops on the physical data ports that are designated for alternate stacking. Then,
when stacking is enabled (with the enable stacking command), those ports – listed in the
Alternate Stacking Ports column of Table 114 – operate using the stacking protocol for the logical
stacking ports.
Table 114: Native and Alternate Stacking Ports
Switch Model Type or location of Native
Stacking Ports
Alternate Stacking
Ports
Location of Alternate
Stacking Ports
X440-24t-10G
X440-24x-10G
X440-24p-10G
None 25,26 Front panel
X440-48t-10G
X440-48p-10G
None 49,50 Front panel
X450a-24t
X450a-24tDC
X450a-24x
X450a-24xDC
X450e-24t
X450e-24p
Fixed (rear panel) 25,26 XGM2-2xf or
XGM2-2xn or
XGM2-2sf or
XGM2-2bt
X450a-48t
X450a-48tDC
X450e-48t
X450e-48p
Fixed (rear panel) 49,50 XGM2-2xf or
XGM2-2xn or
XGM2-2sf or
XGM2-2bt
X450-G2-24t-10GE4
X450-G2-24p-10GE4
Fixed (rear panel) 27,28 Front panel
X450-G2-48t-10GE4
X450-G2-48p-10GE4
Fixed (rear panel) 51,52 Front panel
Using Ethernet Ports for Stacking (SummitStack-V
Feature) Building Stacks
244 Summit Family Hardware Installation Guide