I recently installed a 2.4GHz-only smart bulb on my 2.4/5GHz WiFi using band steering, and I discovered that the bulb can't connect to my WiFi unless I split 2.4 and 5GHz under two different SSIDs.

From what I knew about 802.11, I thought that a device only supporting 2.4GHz wouldn't be affected by the fact that the access point advertises itself under the same SSID on 5GHz.

I've read some articles on the internet that partially covered the subject, but I couldn't find a technical reference.

Why do I have to split the bands? What are the mechanisms that prevent my smart bulb from associating with my WiFi? Are there 2.4GHz-only devices that are able to deal with 2.4/5GHz WiFi using band steering? Does the issue pertain to an unsplitted band or band steering only? In other words, is the issue resolved if the access point advertises itself under the same SSID on both bands but does not utilize band steering?

PS: My question is more about "what are the technical reasons behind this issue" than "I want to connect my bulb without splitting." That's why I don't provide information about the brand of my bulb and access point.

  • 3
    I have partial knowledge on this. Here goes: With some types of band steering, connections on 2.4 will fail for a few times, to encourage the device to try 5GHz. But that may be beyond the bulb's retry limit and hence, you are having to have different SSIDs. Do you need the band steering to be enabled at all ? Arent most of your non-IoT devices new, using 5GHz anyway ? Dec 18, 2023 at 21:10
  • There are different ways to implement band steering. This page from Cisco show two different techniques used in different version of firmware for instance. It would probably help a lot if you told us what AP model and what IoT device you use.
    – jcaron
    Dec 18, 2023 at 22:11
  • This is more common than you think. My Samsung Fridge and old ipads (being used for AV automation) are like that too. Dec 19, 2023 at 4:19
  • @jcaron Thanks for your answer! My question is more about the reason behind the issue rather than the "how to fix it" aspect (I updated the question accordingly). If I understand correctly, the problem is only about band steering? If it is disabled but the same SSID is used on both bands, there are no remaining issues. Is it right that this mechanism is not part of the 802.11 standard, and therefore, some vendor implementations of band steering could cause problems even if the 2.4GHz-only device is brand new?
    – MarcAntony
    Dec 19, 2023 at 10:45
  • @kalyanswaroop Thanks for your response! My reply to jcaron is also directed to you.
    – MarcAntony
    Dec 19, 2023 at 10:47


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