Benefits of running 2 Wi-Fi networks from the same router? What are the downsides? (I don't know if there is a better community for this question)

submitted by unknowing8343 edited

I am worried that there is not really a benefit of doing that, just more noise and energy consumption.

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dan , edited

Energy consumption is essentially the same, as it's using the same radios.

For what it's worth, I have several SSIDs, each on a separate VLAN:

  • my main one
  • Guest. Has internet access but is otherwise isolated - Guest devices can't communicate with other guest devices or with any other VLANs.
  • IoT Internet: IoT and home automation devices that need internet access. Things like Ecobee thermostat, Google speakers, etc
  • IoT No Internet: Home automation stuff that does not need internet access. Security cameras, Zigbee PoE dongle (SLZB-06), garage door opener, ESPHome devices, etc

(to remotely access home automation stuff, I use Home Assistant via a Tailscale VPN)

Most of these have both 2.4Ghz and 5Ghz enabled, with band steering enabled to (hopefully) convince devices to use 5Ghz when possible.

This is on a TP-Link Omada setup with 2 x EAP670 ceiling-mounted access points. You can create up to 16 SSIDs I think.

unknowing8343 [OP]

That was an amazing read. Thank you.

What do you say is the use case for separating guest Wi-Fi with the more "private" stuff on your network?

As far as I understand... Basically all communications, even inside a network, are encrypted... So I guess you do that to avoid someone trying to exploit some vulnerability?

BearOfaTime , edited

Basically all communications, even inside a network, are encrypted

LOL, oh no.

Even internet traffic isn't encrypted by default.

Sadly TCP/IP isn't encrypted.


I think the main benefit is that Guests devices on your network can't find and exploit your own devices.


Guest devices can't communicate with other guest devices

How do you accomplish this isolation since they're on the same subnet/broadcast domain? Is it a feature of the hardware you're using?


Are we talking main + guest network, or 2,4GHz + 5GHz, or something else?


What benefit do you hope to get?


Whether it has benefits is up to you, but from a technical perspective they're as expensive as VLANs, so basically free. It's the same receive and transmit radio, the only difference is that it broadcasts and responds to two network names at the same time. The maximum power consumption is the same: the max the radio will pull when at full load. The minimum power consumption has to be ever so slightly more since it needs to broadcast two network IDs, but those are measured in bytes and sent a couple times a second, it's negligible compared to the cost of just running the radio.

BeatTakeshi , edited

I remember reading a few self hosters describing having a separate WiFi for IoT devices, on a dedicated router (opensense) so they can prevent these devices "calling home". They are maybe other advantages like having different WiFi channels for these things


Separate subsets, segregated traffic. Easy to avoid crosstalk by setting channels further apart or using 2.4ghz and 5ghz

At home I have one SSID as a main wifi, and the other is guest wifi and IoT or other random devices.

Main downside is getting it setup and maintenance.


I'm not sure that I understand the "more noise and energy consumption" part, since we're still talking about the same router with the same connected devices.

But I do have multiple SSIDs on my router. One is explicitly for IoT devices, and they don't have network access, so they are isolated from my computers, NAS, etc.


I am worried that there is not really a benefit of doing that, just more noise and energy consumption.

If there wasn't a benefit, why would people (and pretty much every business) do it?


I think most wifi routers segregate the two networks, so they can't see devices on eachothers network.

Someone will surely correct me if I'm wrong in this.


I'd say that depends. Some consumer routers may have guest network and client isolation on it though I doubt most do. Higher end routers support vlans can be configured that way and could be configured in many other wise such as talking to network 1 but not 2 or 3. For instance, I have IOT vlan allowed to connect to my server vlan for DNS since I self host DNS, but my general VLAN for personal trusted devices does can't be accessed by IOT.