Cisco C9550 Series Smart Switches Hardware Installation Guide

Rear-panel components

Updated: July 17, 2026

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Describes the rear-panel components of C9550 Series Smart switches.

The rear panel of C9550 Series Smart switches include fans and power supply modules.

Rear panel of a C9550-48L4CD — Figure 1. Rear panel of C9550-24L4CD, C9550-48L4CD


1	Power supply units (PSUs) When viewed from the rear, PSU0 is on the right side and PSU1 on the left side.	7	Status LED
2	1PPS (I/O) DIN port	8	Blue beacon
3	TOD PTP RJ-45 port	9	M2 SSD LED
4	RJ-45 console port	10	RJ-45 management port
5	10MHz (I/O) DIN port	11	Fan tray assembly When viewed from the rear, fans are numbered from right to left and starts from 1. 0 is reserved for the blank slot.
6	USB 3.0 port	12	Power supply LEDs


1	Power supply units (PSUs) When viewed from the rear, PSU0 is on the right side and PSU1 on the left side.	8	Fan tray assembly When viewed from the rear, fans are numbered from right to left and starts from 1. 0 is reserved for the blank slot.
2	1PPS (I/O) DIN port	9	PSU LEDs
3	Status LED	10	10MHz (I/O) DIN port
4	Blue beacon	11	Location for attaching system ground
5	M2 SSD LED	12	USB 3.0 port
6	TOD PTP RJ-45 port	13	RJ-45 management port
7	RJ-45 console port	14	Fan LED

Fan modules

The Cisco C9550 Series Smart switches have fan modules at the rear of the switch. The fans are hot-swappable and numbered from right to left.

The 1RU models of the C9550 Series Smart switches support five 22,000 or 30,000 rpm fan modules and 2RU models support three 15,000 rpm fan modules. These fan tray units support N+1 redundancy and are field-replaceable. The minimum number of fans required for the switch to operate is four for 1RU models and two for 2RU models.

This section describes the different types of fan modules that the different SKUs of C9550 use.


1	Fan LED	4	Extraction handle
2	Exhaust vent	5	Retainer clip
3	Airflow direction


1	C9550-FAN-2U	3	Extraction handle
2	Fan LED	4	Retainer clip

1RU models of C9550 Series Smart switches support C9550-FAN-1U fans, and 2RU models support C9550-FAN-2U fans.

C9550-FAN-1U-F and C9550-FAN-2U-F fans with the blue handle support port-side exhaust. C9550-FAN-1U-R and C9550-FAN-2U-R fans with the burgundy handle support port-side intake. You can chose direction of the airflow; either port-side intake or port-side exhaust. All fans must be of the same type, and a mix of the two types of fans is not supported.

Table 1. Switch models and supported fan models
Switch model	Number of fans	Fan model
C9550-24L4CD	5 x 40x40 mm fan trays	C9550-FAN-1U-F: port-side exhaust (blue handle) C9550-FAN-1U-R: port-side intake (burgundy handle)
C9550-48L4CD	5 x 40x40 mm fan trays
C9550-96L4D	3 x 80x80 mm fan trays	C9550-FAN-2U-F: port-side exhaust (blue handle) C9550-FAN-2U-R: port-side intake (burgundy handle)

Warning

Statement 1093—Avoid Sharp Edges

Risk of personal injury. Avoid sharp edges when installing or removing replaceable units.

Fan LEDs

This section describes the fan LED colors on Cisco C9550 switches.


Color	Description
Off	The fan trays are not receiving power; the fans are not working.
Green	All fans are operating normally.
Amber	One or more fans have encountered tachometer faults.
Red	Tachometer faults in one or more fans have exceeded the maximum limit.
Blue	Blue beacon LED to indicate the slot or location of the fan that requires attention.

Power supply modules

An internal power supply module converts external electrical power (either AC or DC) into the precise DC voltages required to operate the switch's internal components.

The Cisco C9550 Series Smart switches have two internal power supply module slots and support 1+1 power supply redundancy. You can use either one or two power supply modules. By default, these switches ship with one power supply module, and you can purchase more power supply modules when you order the switch or at a later date. The power supply modules are numbered 0 to 1, from left to right. All empty power supply module slots must be filled with a blank module.

Each AC power supply module has a power cord for connection to an AC power outlet. To view the list of available AC power cords, see the section.

This section displays the supported power supply modules and the components of each of these.

Figure 5. 750W and 1100W power supply module


1	Serial number location	4	Blue beacon
2	Air vent	5	AC power cord connector
3	Status LED	6	Extraction handle

The following table describes the supported internal power supply modules.

Table 2. Power supply module part numbers and descriptions
Power supply module	Description
C9K-PWR-750WAC	750W AC Titanium-certified power supply module with port-side exhaust fan
C9K-PWR-1100WAC	I100W AC Titanium-certified power supply module with port-side exhaust fan
C9K-PWR-1100WDC	I100W DC Titanium-certified power supply module with port-side exhaust fan

These power supply modules work with fans that have port-side intake (burgundy color) and port-side exhaust (blue color) air flow.

Default power supply

All switches ship with a default power supply module. All the power supply modules (except the blank modules) have internal fans.

Caution

Do not operate the switch with one power supply module slot empty. Always install a blank module in the empty slot to keep the operating temperature and fan noise lower.

This table displays the default power supply module that ships with each switch model.

Table 3. Supported default power supply
Switch model	Default power supply
C9550-24L4CD	C9K-PWR-750WAC
C9550-48L4CD	C9K-PWR-750WAC
C9550-96L4D	C9K-PWR-1100WAC

Power supply configurations

This section lists the supported power supply combinations for each PID.


Switch model	Supported power supply configuration
C9550-24L4CD C9550-48L4CD	750W AC + 750W AC 750W AC + 1100W DC 1100W DC + 1100W DC
C9550-96L4D	1100W AC + 1100W AC 1100W AC + 1100W DC 1100W DC + 1100W DC

Power supply LEDs

This section describes the LED indicators when two power supplies modules are installed in the switch

Table 4. Power supply module LEDs
LED color	Description
Off	Power supply modules are not working. All power supply modules have failed. Power supply modules are not connected to the AC input. Power supply modules are not installed.
Green	Power supply modules are operating normally.
1Hz Green Blinking	Bootloading mode.
Amber	Power supply warning. The power supply modules are operating in high temperature, high power, and slow fan.
Red	Power supply failure due to the following issues: Fan failure Over voltage Over current Over temperature Output ORING FET fault
Blue	Indicates the slot or location of the power supply module that requires attention.

M2 SSD module

The Cisco C9550 Series Smart switches support pluggable Serial Advanced Technology Attachment (SATA) Solid State Drive (SSD) module. The M2 SATA SSD module slot is located on the rear panel of the switch.

The SSD card is a common card, consists of an M2 SSD module and a mechanical carrier. It is a field replaceable unit.

The SSD module storage capacity ranges are 240GB, 480GB, and 960GB.

The following table lists the M2 SATA modules supported on Cisco C9550 Series Smart switches.


M2 SATA SSD	Description
C9K-F3-SSD-240GB	240GB SATA memory for 1RU SKUs
C9K-F3-SSD-480GB	480GB SATA memory for 1RU SKUs
C9K-F3-SSD-960GB	960GB SATA memory for 1RU SKUs
C9K-F4-SSD-240GB	240GB SATA memory for 2RU SKUs
C9K-F4-SSD-480GB	480GB SATA memory for 2RU SKUs
C9K-F4-SSD-960GB	960GB SATA memory for 2RU SKUs

SSD LEDs

This section describes the SSD LEDs and their status.


LED color	Description
Off	SSD is not installed or no activity.
Blinking green	SSD is active.
Blinking red	After button presses, FPGA drive RED LED blinking and send IRQ to SW.
Red	Ready to eject the SSD from the switch.

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