How to connect WiFi to a specific AP?

[Jeffrey Walton]

On Fri, Jul 19, 2024 at 3:21 PM Bo Berglund <bo.berglund at gmail.com> wrote:
>
> On Fri, 19 Jul 2024 13:04:40 -0400 (EDT), Robert Heller <heller at deepsoft.com>
> wrote:
>
> >Presumably, all of the same named AP are on the same network and are using a
> >shared DHCP server (or shared DHCP client DB), so why should it matter which
> >AP you connect to?  The presumption with this sort of set up is load sharing
> >and expanding signal coverage over a larger area with WiFi clients connecting
> >to a "local" AP (eg the one with the best signal strength).  Why would you
> >want to do something different?
>
> The whole reason for having the AP is that my home is so long (20+ meters) and
> the main router is at the fiber intake in the far end of the house.
> So main WiFi is very weak at the entrance in the other end, which caused me to
> set up the AP in the first place.
>
> The problem is that the device connecting to WiFi can see *both* the extension
> Access Point in the near end of my home (which I want it to connect to) AND the
> main router sitting way back in the other end.
>
> The AP field strength is about -70 dBm whereas the main router's field strength
> is only about -96 dBm at the connecting device's location.
>
> Still for some reason the device connects to the *weak* network rather than the
> strong one...
> And it barely works then and it drops the connection, then reconnects again to
> the same netwotk...
>
> Both the AP and the main router (ASUS units) use the same SSID/passphrase for
> connection.
>
> The main router is a new powerhorse whreas the one used as AP is a cheaper
> router set up as an Access Point on the main LAN. The main router is the DHCP
> server on my LAN and is used also through the AP.
>
> I have realized that maybe there is some internal cashing of the WiFi network
> last connected to on the device and since it was for configuration in my study
> where the main router is it might have cached that network and is now re-using
> it when connecting to WiFi without checking the signal strength...

It sounds like your issue is a little more than connecting to a
preferred access point.

Out of curiosity, do the Wifi access points support Wifi Roaming? Are
they 802.11 ac (Wifi 5) ir 802.11 ax (Wifi 6)? If so, this should not
be a problem.

The ethernet or fiber backhaul is good. I would definitely keep that.

Once thing to check for... disable 802.11 a (5 GHz), and 802.11 b (2.4
GHz). They are old technologies, and they severely degrade throughput.
And they caused my TP-Link 802.11 AC access points to lockup on
occasion when an old cell phone or tablet connected. There's just
nothing good that comes from supporting 1990s and early 2000s wifi
technology nowadays.

For 2.4 GHz, enable 802.11 g/n mixed mode; and for 5 GHz enable 802.11
n/ac mixed mode.

And don't get clever with the channels. Keep them set to Auto. For
Wifi versions like AC and AX, the hardware will do a much better job
of provisioning around congestion in real time.

Jeff