Once I'm connected via telnet to certain CISCO equipment I type "Show inventory" and I get to something like this:

Barragan_3750>show inventory
NAME: "1", DESCR: "WS-C3750G-12S"
PID: WS-C3750G-12S-E   , VID: V06, SN: FDO1129Z9ZJ

NAME: "GigabitEthernet1/0/1", DESCR: "1000BaseLX SFP"
PID:                     , VID:    , SN: H006K022        

NAME: "GigabitEthernet1/0/2", DESCR: "10/100/1000BaseTX SFP"
PID: GLC-T               , VID:    , SN: 00000MTC1444080Z

NAME: "GigabitEthernet1/0/3", DESCR: "1000BaseLX SFP"
PID:                     , VID:    , SN: H006K083        

NAME: "GigabitEthernet1/0/4", DESCR: "1000BaseLX SFP"
PID:                     , VID:    , SN: H006K021        

NAME: "GigabitEthernet1/0/5", DESCR: "1000BaseSX SFP"
PID:                     , VID:    , SN: FNS11190FLE     

NAME: "GigabitEthernet1/0/6", DESCR: "1000BaseSX SFP"
PID:                     , VID:    , SN: P7K08UQ         

NAME: "GigabitEthernet1/0/7", DESCR: "1000BaseLX SFP"
PID:                     , VID:    , SN: H006K032        

NAME: "GigabitEthernet1/0/8", DESCR: "1000BaseLX SFP"
PID:                     , VID:    , SN: H006K040        

NAME: "GigabitEthernet1/0/9", DESCR: "1000BaseLX SFP"
PID:                     , VID:    , SN: FNS14420533     

NAME: "GigabitEthernet1/0/10", DESCR: "1000BaseLX SFP"
PID: GLC-LH-SMD          , VID: V86, SN: FNS16361SG0     

NAME: "GigabitEthernet1/0/11", DESCR: "1000BaseLX SFP"
PID: GLC-LH-SMD          , VID: V86, SN: FNS174002FT     

NAME: "GigabitEthernet1/0/12", DESCR: "1000BaseLX SFP"
PID: GLC-LH-SMD          , VID: V86, SN: FNS183503FS     

Let's take this entry for the example:

NAME: "GigabitEthernet1/0/9", DESCR: "1000BaseLX SFP"
PID:                     , VID:    , SN: FNS14420533 

If I type "show cdp neighbors detail " this is showed:

Device ID: Arquitectura_Salones
Entry address(es): 
  IP address:
Platform: cisco WS-C2960S-48TS-S,  Capabilities: Switch IGMP 
Interface: GigabitEthernet1/0/9,  Port ID (outgoing port): GigabitEthernet0/49
Holdtime : 157 sec

Now we know that I have Arquitectura_Salones connected at GigabitEthernet1/0/9, it's serial number is: FNS14420533 and the IP is:

If I connect via telnet to this equipment and type "show version" this information is showed:

Base ethernet MAC Address       : 00:23:05:46:8B:00
Motherboard assembly number     : 73-9835-09
Power supply part number        : 341-0097-02
Motherboard serial number       : FOC12351HVZ
Power supply serial number      : AZS123206WY
Model revision number           : F0
Motherboard revision number     : A0
Model number                    : WS-C2960-48TC-L
System serial number            : FOC1235Z1W5
Top Assembly Part Number        : 800-26672-04
Top Assembly Revision Number    : A0
Version ID                      : V04
CLEI Code Number                : COM3F00BRC
Hardware Board Revision Number  : 0x02

As you can see, the serial number is different.

How can I know which is the correct one?

  • Which two serial number are you trying to compare? The 'show inventory` command on the 3750G will not show serial numbers on the 2960S, only on the 3750G.
    – Ron Maupin
    Mar 8, 2017 at 20:50

3 Answers 3


Show inventory is for local information only. You are finding the serial number of the 1000BaseLX SFP optic in Gi1/0/9 with this output.

The show inventory and show version on the 2960 should match. Be aware that sometimes the mainboard serial number is sometimes shown with the same description as the device, so double-checking between the inventory and version outputs is recommended.

  • Is there a way to retrieve the connected device's serial number? something like "show CDP neighbors" but with that info. I'm trying to have a record of the devices on a network and SN is my primary key. Mar 9, 2017 at 15:48
  • 1
    @CesarAlejandroVillegasYepez, short answer, no. This is information that is just not sent between devices. You could perhaps use something like SNMP to pull information from connected devices if it is running on them.
    – YLearn
    Mar 11, 2017 at 18:29
  • I'll add that NX-OS devices will append their serial number to CDP advertisements, but that's an isolated case.
    – cpt_fink
    Jun 1, 2018 at 6:00

The show inventory command allows you to view the UDI for a NAM device. This identity information is stored in the NAM device's non-volatile memory.

•PID—Product identification (ID) number of the device

•VID—Version ID of the device. Displays as 0 if the version number is not available.

•SN—Serial number of the device

example :

SW-1#show inve FI-CIS-MRF-SW-1#show inventory NAME: "1", DESCR: "WS-C3750X-48" PID: WS-C3750X-48T-E , VID: V06 , SN: FDO1825Z16G

NAME: "Switch 1 - Power Supply 0", DESCR: "FRU Power Supply" PID: C3KX-PWR-350WAC , VID: V03L , SN: LIT18110PRW

NAME: "Switch 1 - FRULink Slot 1 - FRULink Module", DESCR: "FRULink 1G Module" PID: C3KX-NM-1G , VID: V01 , SN: FDO14381EJN

NAME: "GigabitEthernet1/1/1", DESCR: "1000BaseLX SFP" PID: GLC-LH-SMD , VID: V01 , SN: FNS164802G2

NAME: "GigabitEthernet1/1/2", DESCR: "1000BaseLX SFP" PID: GLC-LH-SMD , VID: V01 , SN: AGA1730U4KS

NAME: "GigabitEthernet1/1/3", DESCR: "1000BaseLX SFP" PID: Unspecified , VID: , SN: OP10G4CE1330


show inventory : Displays the switch type, components (including media), and Dell Networking OS version including hardware identification numbers and configured protocols

Show Version The show version command is very useful. From running the command I can see the following useful pieces of information about my router.

Model Uptime IOS Version & software release CPU, RAM, NVRAM & Flash details Configuration Register setting

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