Using Ethernet Ports for Stacking (SummitStack-V Feature)

On many Extreme Networks switches, you can reconfigure one or two 10-Gbps Ethernet data ports to operate as stacking ports.

This feature, known as SummitStack-V or alternate stacking, means that you can use less expensive cables to connect the switches in a stack. Because copper and fiber Ethernet ports support longer cable distances, you can also extend the physical distance between stack nodes – connecting, for example, switches on different floors in a building or in different buildings on a campus.

The SummitStack-V feature means that you can stack switches that have no dedicated (or native) stacking ports but that do have at least two Ethernet ports. The ports can be configured to support either data communications or stacking. When configured to support stacking, they are called alternate stacking ports to distinguish them from the native stacking ports that use custom cables.

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 different floor.

Note

Note

When you connect distant nodes using alternate stacking ports, be sure to run the cables over physically different pathways to reduce the likelihood of a cut affecting 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 different switches must be directly connected, with no intervening switch connections. This is because alternate stacking ports use the proprietary ExtremeXOS protocol for stacking, not the standard Ethernet protocol.

Native and Alternate Stacking Ports 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 Native and Alternate Stacking Ports – operate as stacking ports.

Table 1. Native and Alternate Stacking Ports
Switch Model Type or location of Native Stacking Ports Alternate Stacking Ports Location of Alternate Stacking Ports
X440-G2-12t-10GE4

X440-G2-12p-10GE4

Fixed (front panel) 15,16 Front panel
X440-G2-24t-10GE4

X440-G2-24p-10GE4

X440-G2-24x-10GE4

X440-G2-24t-10GE4-DC

Fixed (rear panel) 27,28 Rear panel
X440-G2-48t-10GE4

X440-G2-48p-10GE4

X440-G2-48t-10GE4-DC

Fixed

(rear panel, dedicated SFP+ port)

49,50 Rear panel
X450-G2-24t-GE4

X450-G2-48t-GE4

X450-G2-24p-GE4

X450-G2-48p-GE4

Fixed (rear panel) Not applicable Not applicable
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
X460-G2-24t-GE4

X460-G2-24p-GE4

VIM-2ss or VIM-2q 33,34 VIM-2x
X460-G2-48t-GE4

X460-G2-48p-GE4

VIM-2ss or VIM-2q 53,54 VIM-2x
X460-G2-24t-10GE4

X460-G2-24x-10GE4

X460-G2-24p-10GE4

VIM-2ss or VIM-2q 31,32 Front panel
X460-G2-48t-10GE4

X460-G2-48x-10GE4

X460-G2-48p-10GE4

VIM-2ss or VIM-2q 51,52 Front panel
X465 S1 and S2 on front panel N/A N/A
X590-24t-1q-2c

X590-24x-1q-2c

Ports 29, 33 None Not applicable
X620-8t-2x

X620-10x

None 9,10 Front panel
X620-16t

X620-16x

X620-16p

None 15,16 Front panel
X670-G2-48x-4q Ports 49,53,57,61 47,48 Front panel
X670-G2-72x None 71,72 Front panel
X690-48t-2q-4c Ports 61,69 None Not applicable
X690-48x-2q-4c Ports 61,69 None Not applicable
X695-48Y-8C 61, 62 None Front panel
X870-32c Ports 121,125 None Not applicable
X870-96x-8c Ports 121,125 None Not applicable