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
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 Switch Engine protocol for
stacking, not the standard Ethernet protocol.
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
– operate as stacking ports.
Table 7: Native and Alternate Stacking Ports
Switch Model
Type or Location of Native
Stacking Ports
Alternate Stacking
Ports
Location of Alternate
Stacking Ports
5320-48P-8XE
5320-48T-8XE
5320-24P-8XE
5320-24T-8XE
5320-16P-4XE
5320-16P-4XE-DC
Front panel: U1, U2
None
Not applicable
5420F-8W-16P-4XE
5420F-24P-4XE
5420F-24S-4XE
5420F-24T-4XE
5420F-16MW-32P-4XE
5420F-16W-32P-4XE
5420F-48P-4XE
5420F-48P-4XL
5420F-48T-4XE
5420M-24T-4YE
5420M-24W-4YE
5420M-16MW-32P-4YE
5420M-48T-4YE
5420M-48W-4YE
Front panel: U1, U2
None
Not applicable
Use Ethernet Ports for Stacking (SummitStack-V
Feature)
Build Stacks
40
ExtremeSwitching 5320 Series Hardware Installation Guide
