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Cisco Nexus 3000 Series Hardware Installation Guide
OL-25338-04
Chapter 1 Overview of the Cisco Nexus 3000 Series Switches
Cisco Nexus 3172PQ Switch
Caution The switch must run with all of its power supply and fan tray modules taking in air from a cold aisle and
exhausting air to the hot aisle. If they take in air from a hot aisle, an overtemperature condition can occur
and the switch will shut down. If the airflow directions are mixed in the same switch, you will see an
error.
Note Never leave a power supply slot empty. If you remove a power supply, replace it with another one. If you
do not have a replacement power supply, leave the non functioning one in place until you can replace it
or fill the slot with a filler blank module (part number N2200-P-BLNK).
Fan Tray for the Cisco Nexus 3172PQ Switch
The Cisco Nexus 3172PQ switch supports four (3+1) redundant fans, which provide either forward or
reverse airflow for cooling. You can hot swap the fan tray during operations but must replace it within
one minute.
Both forward (port-side exhaust) and reversed (port-side intake) airflow schemes are supported. The
port-side exhaust scheme is used when the cold air flows in through the side having the fans (facing the
cold aisle) and exhausts out of the side having the ports (facing the hot aisle). Port-side intake scheme
is used when the air flows in through the ports (facing the cold aisle) and leaves through the side having
the fans (facing the hot aisle).
Caution You can order a replacement fan tray with forward airflow or reverse airflow. Be sure to order the same
direction of airflow that is used with the switch.
Caution The switch must run with all of its power supply and fan tray modules taking in air from a cold aisle and
exhausting air to the hot aisle. If they take in air from a hot aisle, an overtemperature condition can occur
and the switch will shut down. If the airflow directions are mixed in the same switch, you will see an
error.
Transceiver and Cabling Options for the Cisco Nexus 3172PQ Switch
The Cisco Nexus 3172PQ supports a wide variety of 1, 10, and 40 Gigabit Ethernet connectivity options.
1 and 10 Gigabit Ethernet connectivity is achieved in the first 48 ports, and 40 Gigabit Ethernet
connectivity is achieved using QSFP+ transceivers in the last 6 ports. QSFP+ technology allows a
smooth transition from 10 to 40 Gigabit Ethernet infrastructures in the data center. The Cisco Nexus
3172PQ supports connectivity over copper and fiber cables, providing excellent physical-layer
flexibility. For low-cost cabling, copper-based 40-Gbps Twinax cables can be used, and for longer cable
reaches, short-reach optical transceivers are optimal. Connectivity can be established from the QSFP
ports to an upstream 10 Gigabit Ethernet switch using a splitter cable that has a QSFP transceiver on one
end and four SFP+ transceivers on the other end. Similar capability can be achieved using optical
transceivers by procuring third-party fiber splitters. Table 1-16 lists the QSFP transceiver types
supported.