1

I've been running into issues getting devices connected to the 2.4 GHz band of my router (TP-Link Archer C7). Note that 5 GHz works fine, no issues at all. Devices in question include Lenovo Y500 laptop, iPhone 6S+, Lenovo Android tablet.

I've tried adjusting the channel for the 2.4 GHz band, changing passwords and SSIDs, upgrading router firmware, router factory reset, all to no avail. Something weird that I'm noticing is that when I try to connect to the default SSID (TP-LINK_FB60) on my iPhone it has two separate behaviors:

  • Enter correct password: Popup says "Unable to connect to TP-LINK_FB60", then after tapping confirm another popup says "Unable to connect to LAN Before Time 2" (that was my SSID before running into troubles and resetting to factory). Why would it do this? Does it recognize the router and remember past SSIDs despite it changing?

  • Enter incorrect password: Popup says "Unable to connect to TP-LINK_FB60". That's it.

So there's definitely some sort of conflict going on with the iPhone at least. For the laptop I've tried making it forget the past SSIDs, ipconfig /flushdns, /release, /renew. It can connect for short periods of time (<10 minutes).

This is odd to me, that several makes and models of devices would have this issue with that particular band of WiFi. Furthermore, this is the second replacement router after the original failed. The last one was a refurbed Linksys E4500 which had the same issue I have now (I assumed it was the router's problem).

Any ideas as to why the 2.4 GHz band in my situation is so shaky?

Router configs:

  1. Concurrent 2.4/5 GHz broadcasting
  2. WPA2 Personal AES
  3. 2.4 GHz: bgn mixed
  4. 5 GHz: a/n/ac mixed
3
  • I had issues with multiple devices when the router was running in concurrent mode (same SSID for both bands); took me days to find. I have now set the router back to two separate SSIDs for the two bands, and it is fine again.
    – Aganju
    Sep 5, 2016 at 1:22
  • I see, that interesting. I always use separate SSIDs for each band but I could see that being an issue otherwise. Thanks for the input Sep 6, 2016 at 16:24
  • Related: askubuntu.com/q/1196348/327339. Here's my solution: askubuntu.com/a/1271252/327339. Aug 30, 2020 at 7:59

3 Answers 3

1

It would appear that explicitly setting the channel width to 20 MHz has fixed my issue. Before that option was set to auto.

I live in an apartment building so I'm guess there's some serious interference going on, especially if I try to span 40 MHz in the 2.4 GHz band. Using 20 MHz I no longer have dropping connections (so far anyway), and devices that couldn't connect at all before are able to now.

1
  • Yeah I've seen a cordless phone completely shut down 2.4GHz Wi-Fi that was in 40MHz 802.11n mode. The older Atheros 108mbps Wi-Fi equipment automatically switches to 40MHz mode only when needed and only when there is no interference, but N doesn't do this. Mar 21, 2019 at 1:58
0

This might sound silly, and I'm almost positive it's NOT this, but it's worth checking....Log in to your router and make sure that DHCP is enabled. It might also be worth checking if new devices are allowed to connect without you having to enter their MAC Address to the list, (I currently do this, keeps the neighbours from trying to piggy back on my network).

I don't mean to imply anything about your intelligence, it's something really easy and simple but most people who know quite a bit about computers will overlook those settings, thinking, "it's something I can't figure out. It must be REALLY complicated, then!!", even doing this for days, and then there's a moment of clarity when they go through the router page by page by page......and all their family members suddenly hear the sound of an open palm slapping the computer user's own forehead, and once again all is right with the world.

Like I said, probably not that, but worth a look, just in case. It might also be worth turning off DHCP, (if it's not already off), and giving all the devices a manual LAN IP so there's no clashing of addresses.

EDIT After some searching, some users have found success by changing the wireless password from WPA2 to WPA2 MIXED

1
  • I always have DHCP enabled, I'm not interested in setting IPs manually lol. The security idea is good but I had already tried disabling it completely (same issue). Thanks for your input though, see my answer if interested Sep 6, 2016 at 16:22
0

For more than a year I had the same issue, I was not able to use "free wifi" anywhere because they were all 2.4GHz. I have finally figured it out.

In Wi-Fi properties > Networking > Configure... > Advanced

For 802.11a/b/g Wireless Mode change the value to "6. Dual Band 802.11a/b/g" instead of "1. 5GHz 802.11a"

I have no idea why it was set up this way, I had installed a fresh OS.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .