Trunks Of Ports S1 And S2 - Allied Telesis AlliedWare Plus Installation Manual

Chapter 2: Virtual Chassis Stacking

Trunks of Ports S1 and S2

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Front-panel ports S1 and S2 are the default trunk ports on x930 Switches,
except for switches containing AT-StackQS Cards, in which case their
ports are the default trunk ports. The ports are 27/S1 and 28/S2 on 28-port
switches and 52/S1 and 52/S2 on 52-port x930 Switches. Here are the
guidelines:
Stacks with trunks of ports S1 and S2 can have up to eight x930

Switches.
Stacks can have both 28- and 52-port switches.

Ports S1 and S2 support a variety of short and long distance fiber

optic SFP+ transceivers and direct connect cables. You may use
any of the supported transceivers for the trunk. Refer to the
product's data sheet on the Allied Telesis web site for a list of
supported transceivers. Transceivers are purchased separately.
The SFP+ transceivers or direct connect cables must be from

Allied Telesis. Switches with transceivers from other network
equipment providers might not form the stack.
The cables must crossover to different ports in the switches of the

stack. Port S1 in one switch has to crossover to port S2 in the next
switch. Additionally, the ports on the cards in the first and last
switches of the stack have to be connected together to form a loop
in the trunk.
You can use ports S1 and S2 as regular networking ports by

disabling VCStack or selecting other ports as the stack trunk.
For switches that have AT-StackQS Cards, you have to perform

the STACK ENABLE BUILTIN PORTS command to use ports S1
and S2 as the trunk ports.
The bandwidth of the trunk is 40Gbps.

For instructions, refer to Chapter 11, "Building the Stack with SFP+ Ports
S1 and S2" on page 147.
An example of a stack trunk for two switches is illustrated in Figure 18 on
page 61.