Enterasys A4H124-24, Hardware Installation Manual

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Connecting Stacking Cables
Enterasys A4 Fast Ethernet Switch Hardware Installation Guide 2-5
Figure 2-3 Fastening the Switch to the Rack
3. If you are installing this switch in a stacked configuration, repeat this procedure for each
switch until all switches have been installed in the stack, then proceed to “
Connecting
Stacking Cables ” on page 2-5. Otherwise, proceed to “ Connecting AC Power ” on page 2-9.
Connecting Stacking Cables
The stack of switches can be connected in a closed loop or daisy chained. In a closed loop all the
switches are connected in sequence and the last switch in the stack is connected back to the first
switch. In a daisy chain configuration the cable that would return the connection back to the first
switch in a closed loop is not installed. The advantage of the closed loop is redundancy, this
configuration eliminates any single point of failure. Up to eight switches can be stacked together
and connected by standard UTP Category 5 or better cables. The stacking cables allow the entire
stack to operate with a single IP address.
Figure 2-4 shows an example of a four-high stack connected in a closed loop configuration. All
STACK DOWN and STACK UP connectors are used in the installation. The stacking cable
connections are from the STACK DOWN connector of one switch to the STACK UP connector of
the next switch up in the stack. A stacking cable connection from the STACK DOWN connector of
the switch at the top of the stack to the STACK UP connector at the bottom of the stack closes the
loop. In a daisy chain configuration, one cable connection is not made.
1 Rails of 19-inch rack 2 Mounting screws (customer-supplied)