Using the example, I will update the firmware on several switches, DES-3200-10, DES-3200-26, DES-3200-28.
How to update the firmware on the D-Link DES-3200 C1, see my article:
Firmware Update D-Link DES-3200 C1
First of all, we will find the latest version on the official sources of D-Link and save it on the TFTP server:
At the time of writing, the firmware revisions for switches A1 and B1 are the same.
How to start a TFTP server can be found in my articles:
Starting a TFTP server in Windows
Installing and Configuring a TFTP Server in Ubuntu
Connect to the switch via telnet, see what firmware is bootable (for example, version 1.21 was installed on one of the switches in image_id 1, and in image_id 2 it is empty):
show firmware information
Now download the firmware file from the TFTP server to the switch as image_id 2:
download firmware_fromTFTP 192.168.1.5 DES-3200R_1.91.B06.had image_id 2
Let’s make the firmware file under image_id 2 the main boot:
config firmware image_id 2 boot_up
Reboot the switch so that it starts with the new firmware:
After updating the firmware, the settings remained unchanged.
On D-Link switches, the DES-3200 B1 often noticed a spontaneous reset when the power went out, a firmware update did not help, so they were replaced with the A1, C1 revision switches, probably got a defective party.