How to Identify a Data Center Switch by PID, VID, and Serial Number and Order a Compatible Replacement

On a Cisco data center switch, the PID (Product ID) is the model, the VID (Version ID) is the hardware version of that model, and the serial number identifies one physical unit. Those three values name the chassis. They do not say whether a replacement will work in the rack it goes into. A data center switch also has power supplies and fans with a fixed airflow direction, optics in its ports, a peer it pairs with, and an operating mode and licenses tied to the chassis. A compatible replacement accounts for all of them.

Identifying a data center switch and ordering its replacement takes six steps:

1. Read what the PID, VID, and serial number identify.
2. Record all four layers from the rack and the CLI.
3. Pull the as-ordered configuration by serial number.
4. Check the six fit points.
5. Choose like-for-like or a newer model.
6. Build the replacement order.

What PID, VID, and Serial Number Identify on a Data Center Switch

Identifier	What it identifies	Example	Use in a replacement
PID	The orderable model	N9K-C93180YC-FX3, DS-C9148V-48PETK9	Decides what gets ordered
VID	The hardware version of that PID	V01, V02	Kept in the asset record; rarely changes the order
Serial number	One physical unit	Printed on the chassis label	Retrieves Cisco’s record of how the unit was ordered

The PID coded on the hardware is the base PID. Under Cisco’s Unique Device Identifier (UDI) standard, an orderable PID can also describe a packaging option or a bundle sold, tested, and shipped together.

On some data center switches, the PID carries part of the configuration. Cisco’s MDS 9148V data sheet (July 13, 2026) lists the DS-C9148V-48PETK9 as 48 active ports with 48 32G shortwave optics and port-side exhaust airflow. The DS-C9148V-48PITK9 is the same switch with port-side intake, and the DS-C9148V-24EK9 has 24 active ports and no optics. On Nexus switches, airflow is in the power supply and fan PIDs instead: NXA-PAC-650W-PE is port-side exhaust, NXA-PAC-650W-PI is port-side intake.

Cisco increments the VID when it makes a notable change to a product and publishes VID changes in product change notices (PCNs).

The chassis label position varies by model; How to Find a Cisco Serial Number shows where to look.

Record All Four Layers from the Rack and the CLI

A data center switch is identified at four layers. On Nexus and MDS switches running NX-OS, these commands read each one:

Layer	What to record	Where to read it
Chassis	PID, VID, serial number	Chassis label; “Chassis” row of show inventory
Field-replaceable parts	Power supply and fan PIDs and quantities; supervisors, line cards, and fabric modules on a modular chassis	show inventory, show environment power, show environment fan
Ports	Optic or cable type in each port, breakout cables	show interface transceiver
Role and configuration	Leaf, spine, or SAN fabric A or B; vPC peer PID; NX-OS or ACI mode; software release; licenses	show version, show license usage, and show inventory on the peer

show inventory prints one entry per part. This excerpt is from Cisco’s NX-API reference for a Nexus 9508:

NAME: "Chassis",  DESCR: "Nexus9000 C9508 (8 Slot) Chassis"
PID: N9K-C9508           ,  VID: V03 ,  SN: FGE20330LWZ
NAME: "Power Supply 1",  DESCR: "Nexus9000 C9508 (8 Slot) Chassis Power Supply"
PID: N9K-PAC-3000W-B     ,  VID: V02 ,  SN: DTM190203NX

Check airflow on the modules as well as in the command output. Fan and power supply modules are color-coded: on the N9K-C93180YC-FX3, burgundy is port-side intake and blue is port-side exhaust. Cisco Field Notice FN72006 (April 2023) covers some N9K-C9508-FAN and N9K-C9516-FAN trays where show environment fan reports front-to-back airflow while the actual flow may be back-to-front.

Pull the As-Ordered Configuration by Serial Number

When a switch no longer boots, sits in a remote facility, or appears only as a serial number in an asset sheet, the serial number is the quickest route back to its original configuration. A lookup returns the PID, the service level and end date, and a component list from Cisco’s installed-base record (the products and services Cisco ties to each serial number), one line per installed part.

Enter the chassis serial number in the Layer23-Switch Cisco Serial Number Check: sign in, enter one serial number, complete the security check, and select Check. For 20 or more serial numbers, the tool page has a CSV template to fill in and send.

The component list returned for one N9K-C93180YC-FX3 in October 2026, with the serial number removed:

Returned line	Qty	What it tells you	In the replacement order
NXA-PAC-650W-PI	2	AC power supplies, port-side intake	Same PID, 2
NXA-FAN-35CFM-PI	4	Fan modules, port-side intake	Same PID, 4
NXK-AF-PI	1	Cisco’s dummy PID for the airflow chosen at order time; not a physical part	Same PID
MODE-ACI-LEAF, ACI-N9KDK9-15.2	1 each	Ordered as an ACI leaf with release 15.2	The mode the switch runs now, current release
SFP-10/25G-CSR-S, QSFP-100G-SR1.2	48, 6	Downlink and uplink optics	Reuse if healthy
NXK-MEM-16GB, NXK-ACC-KIT-1RU, C13-C14 power cord (regional PID)	1 each	Extra memory, rack kit, power cord	Same; one cord per power supply

Two rules apply when reading the result:

• Count parts by serial number, not by rows. A part covered by two service contracts appears once per contract. One N9K-C93180YC-EX lookup listed four NXA-PAC-650W-PE rows and eight NXA-FAN-30CFM-F rows; with duplicate serial numbers removed, that is two power supplies and four fans.
• The result shows how the switch was ordered. It carries no running configuration (VLANs, interfaces, routing) and no parts swapped in the field.

Check the Six Fit Points Before Ordering

A replacement fits when six things match the switch it replaces:

Fit point	Where it shows	If it differs
Airflow	-PE or -PI on Nexus power supply and fan PIDs; E or I in an MDS 9148V PID	The switch overheats or shuts down
Power	Power supply PID: AC, DC, or HVAC/HVDC, and wattage; power cord type	Supplies or cords do not match the rack’s power feed
Ports and optics	Port layout on the data sheet; show interface transceiver	Existing optics and cables cannot move across
Role and pairing	vPC peer PID; SAN fabric A or B	The pair does not form or is unsupported
Software and mode	show version; mode selection PIDs such as MODE-ACI-LEAF	The new hardware needs a newer release; the configuration must be rebuilt
Licenses	License PIDs; active-port count in an MDS PID	Ports stay inactive or features are missing

Two of these need more than a PID comparison.

Airflow. Every fan and power supply in a switch must move air in the same direction, and the port side must face the aisle that direction expects: port-side intake in the cold aisle, port-side exhaust in the hot aisle. The N9K-C93180YC-FX3 hardware installation guide (October 2026) warns that a mix can overheat the switch and shut it down. The MDS 9148V hardware installation guide is more specific: with a mismatched fan module, the switch shuts down in 10 to 15 seconds; with a mismatched power supply, after 10 minutes.

Pairing. For vPC in NX-OS mode, Cisco’s NX-OS 10.6(x) interfaces configuration guide does not support different Nexus 9000 generations in one vPC domain. Cisco’s hardware-refresh procedure for Nexus switches (September 2025) replaces both peers and keeps the vPC between an old and a new switch down during the change. ACI fabrics follow the Cisco ACI design guide (June 2024), which requires both vPC leaf switches to be the same switch generation.

Choose Like-for-Like or a Newer Model

Situation	Identify first	Replacement
Failed leaf or spine, model still orderable	Base PID, airflow, mode	The same PID with matching power supplies and fans
Model no longer orderable	The replacement named on Cisco’s support page for the model	The newer model, with every fit point checked again
SAN switch	Active ports, optics, and airflow in the PID	The same PID, or a base PID plus port licenses such as M9148V-PL8 (8-port upgrade)

Cisco’s support page for the N9K-C93180YC-EX names the N9K-C93180YC-FX3 as its replacement. Set against the FX3 data sheet (October 9, 2026), the parts from the N9K-C93180YC-EX lookup above compare like this:

On the N9K-C93180YC-EX	On the N9K-C93180YC-FX3	Order action
NXA-PAC-650W-PE ×2	Listed as a supported power supply	Same PID works
NXA-FAN-30CFM-F ×4	Not listed; the FX3 takes NXA-FAN-35CFM-PE or NXA-FAN-35CFM-PI	Order four new fans in the same airflow
NX-OS 7.0(3)I4(2), as shipped	Minimum NX-OS 9.3(7) or ACI 15.1(3)	Rebuild the configuration for a current release
48 × 10/25G and 6 × 100G QSFP28 ports	48 × 1/10/25G SFP28 and 6 × 40/100G QSFP28 ports	Port layout matches; check each optic in Cisco’s optics compatibility matrix
vPC peer is another N9K-C93180YC-EX (NX-OS mode)	Different generations in one vPC domain are not supported	Replace both peers

When the replacement should also add speed or port density, the Data Center Switch Buying Guide covers sizing a new design. MDS port licenses are covered in the Cisco MDS 9100 Port License Guide.

Build the Replacement Order

The order follows the four layers:

• Chassis. Read the description of any PID that ends in “=”. Cisco lists the N9K-C93180YC-EX= as “Spare (No Acc kit, PS & fan)”, meaning no accessory kit, power supplies, or fans, while the DS-C9148V-24EK9= includes four fans and two power supplies.
• Power supplies and fans. Same airflow as recorded, plus the airflow selection PID where the platform uses one, such as NXK-AF-PI.
• Mode, software, and licenses. As the switch runs now, not as it shipped.
• Power cords. One per power supply, matched to the rack’s power distribution units.
• Optics. Reuse the ones that read correctly in show interface transceiver.

A quote request moves fastest with the serial number lookup result or the show inventory output, the airflow direction and power type, the operating mode and release, the PID of any vPC peer or fabric partner, and the quantity and delivery date.

Run the chassis serial number through the Cisco Serial Number Check, then send the result with a quote request. Current models are listed under Cisco data center switches, including the Nexus 9000 and MDS 9100 series.

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