On the test I will use the D-Link DGS-3120 rev.A1 switch with Boot PROM V.2.00.003 and firmware 3.00.B026.
Download the new firmware for the required revision from the official site
http://forum.dlink.ru/viewtopic.php?f=2&t=92700&sid=04ae57db59e0b60948ad8e76ecbbe0db
At the time of this writing, I downloaded version v3.10.B028 under rev.A1/A2.
After downloading, put the firmware file on the TFTP server.
If you want to see how to start the TFTP server in my articles:
Starting a TFTP server in Windows
Installing and Configuring a TFTP Server in Ubuntu
Now we connect to the switch via telnet or console cable and execute a command that shows the revision and firmware version of the switch:
show switch
Download the firmware to the switch from the TFTP server:
download firmware_fromTFTP 192.168.1.2 src_file DGS3120_Run_3_10_B028.had dest_file DGS3120_Run_3_10_B028.had
We indicate that when turned on, the switch should boot from it:
config firmware image unit 1 DGS3120_Run_3_10_B028.had boot_up
Reboot the switch:
reboot
Through the switch’s web-interface, you can also update the firmware by opening the Tools tab at the top – “Download Firmware”.
You can update the firmware either through a TFTP server or through an HTTP interface by selecting the firmware file on the computer.
After the firmware, the switch settings remained unchanged.
I updated the firmware remotely.