@Arion 

On the note for firmware upgrade, the v4.20 is only available for 4.20, and v4.0 only available for 4.0. Also you can see that the file size is different. I think that they are not compatible.

I still need an official answer from TP-Link staff.

Sometimes developers say that decimal version difference is not version difference. Even in this case, firmware update for 4.26 is written officially the same file as for 4.20

The website suggests that the firmware should be compatible, specifically, on the v4 firmware page, it says Normally V1.x=V1.

Also, for How to find the hardware version on a TP-Link device under the heading "For products with management interface:" it says "There is a character string “Ver:X.Y” (for example, Ver:1.0) in the Serial Number field, and the number X is the hardware version of the device. If the string is “Ver: 1.1”, normally it means that the hardware version is V1."

The v4 firmware on the website is 437.51 KB while the v4.2 and v4.26 each have two updates of 438.09 KB and 437.51 KB. It's not clear if the slight size difference is significant.

However, the v4.2 firmware update says it's for hardware version 4.2, and the v4.26 update says it's also for hardware v4.2.

If the v4.2 hardware is incompatible with v4, they should have just bumped it up to v5 for clarity. I also don't understand why both 4.2 and 4.26 appear as distinct entries in the drop-down list.

What a mess.

The last time I tried a firmware update on a TP-Link device, it bricked, so I guess I'm not doing anything until this versioning issue is explained.

@Arion 

Hi,

Recently I purchased a (TL-SG1024DE(UN)_v4.0_20191128), then went looking to update firmware.

Firmware Version    1.0.0 Build 20191128 Rel.43130
Hardware Version    TL-SG1024DE 4.0

Does anyone have an official answer if 4.XX Firmware can be applied to Hardware 4.0 ?

What is the differences in the updated Hardware / Firmware and fixes ?

Advice ? if it works sit on your hands ?

Cheers,

R

The local representatives usually know sh*t, they rather say that you can't use this update for lower version, even if the official text on every firmware page claims 1.x is considered the same version.

The main question is, do you have any issue with the latest firmware installed? If you don't have any, if it works fine, it's better leaving it that way.

I know it gives an unsecure feeling having a 3-year-old firmware on a network device but let's hope it's been coded and refined well, it's not a sophisticated hardware like L3 switches, just an "easy smart".

I've left mine with the factory firmware. I don't want to risk bricking another TP-Link device (I bought a TP-L router once. Never again.)

That said, make sure the firewall and/or router in your network is fully patched with the lastest firmware.

@Fae 

The documentation on the site should be modified accordingly.

For How to find the hardware version on a TP-Link device under the heading "For products with management interface:" it says:

"There is a character string “Ver:X.Y” (for example, Ver:1.0) in the Serial Number field, and the number X is the hardware version of the device. If the string is “Ver: 1.1”, normally it means that the hardware version is V1."

From what you've said '1.1' is no longer  V1 -- which contradicts the FAQ.

Fae wrote

Generally speaking, hardware version x.2 and x.0 are different versions, while hardware version x.28 (or x.26) is equal to x.20, similarly, hardware version x.8 (or x.6) is equal to x.0.

 

So the TL-SG1024DE 4.20 firmware cannot be applied to TL-SG1024DE 4.0 since the 4.20 and 4.0 are different versions.

While the TL-SG1024DE 4.26 firmware can be used on TL-SG1024DE 4.20.

  @Fae 

On the V4 firmware page, it says:

(Normally Vx.0=Vx.6/Vx.8 (eg:V1.0=V1.6/V1.8);   Vx.x0=Vx.x6/Vx.x8 (eg:V1.20=V1.26/V1.28)

So, I would expect my V4.0 hardware would work with v4.2. 

Will the average person realize that v4.2 and v4.20 are different and therefore incompatible?

Again, I wish for clarity's sake that the hardware version had jumped to 5.