squirrelpie
Posts: 21
Joined: Fri Dec 13, 2019 8:49 pm

SOLVED: can't connect to new wifi repeater

Thu Jan 16, 2020 4:40 pm

I just bought a new wifi repeater. It's a Netgear EX6120. I'm using a Pi 3 Model B+ to configure it with its web browser, since I couldn't get WPS to work. I have managed to connect to its configuration page on the NETGEAR_EXT net and have configured the repeater. The repeater seems to be working - my main router reports two new devices in its WLAN client list, which I presume are the repeater's 2.4GHz and 5 GHz connections, and I have been able to connect my phone to the new MYSSID_2GEXT net that the repeater is serving. The lights on the repeater are also as expected, with green for router and power and WPS.

But the device light is off on the repeater, and the pi 3B+ has no networking :(
I've been unable to get the pi to restart its networking and am looking for help with that.

I need (well desire) to restart the network without rebooting the pi, because the repeater's web page is still open on the pi's screen and I am supposed to click on that page AFTER restarting the pi's network with a connection to the repeater's MYSSID_2GEXT net, in order to complete configuration of the repeater.

I have tried various things such as sudo ifconfig wlan0 up and sudo systemctl restart network.service and I've made sure wpa_supplicant.conf looks sensible. But the network widget says 'eth0:stopped wlan0:stopped' when I hover over it and 'No wireless interfaces found' when I click on it. sudo iwlist wlan0 scan shows the original nets from the router and the new nets from the repeater though, so clearly the network hardware is still actually there and working.

Since I don't have a working network on the pi, it's a bit difficult to provide content of files or output from commands, hence the sketchy details I've provided. (I can't restore the ethernet connection because it conflicts with the repeater's setup addresses.)

Can anybody suggest what to try, or point me to an up-to-date how-to on troubleshooting wlans on pis?
Last edited by squirrelpie on Fri Jan 17, 2020 5:22 pm, edited 1 time in total.

squirrelpie
Posts: 21
Joined: Fri Dec 13, 2019 8:49 pm

Re: can't connect to new wifi repeater

Thu Jan 16, 2020 10:41 pm

No suggestions yet. :( Maybe I've confused people.

Just to be clear, I think my problem is entirely confined to the Raspberry Pi 3 Model B+. I believe the repeater is working properly.

I think my problem is due to something I have done to the pi whilst trying to get the repeater working, and maybe made worse trying to get the networks to come back up afterwards. I don't understand much about wifi in general and very little indeed about how it works on the pi specifically. I did a lot of searches and tried various commands, none of which worked but may have been inappropriate on my new buster system.

One more datapoint. I took the LAN connection down because of the address conflict using sudo ifconfig eth0 down but now when I type sudo ifconfig eth0 up there's no output but eth0 doesn't connect.

squirrelpie
Posts: 21
Joined: Fri Dec 13, 2019 8:49 pm

Re: can't connect to new wifi repeater

Fri Jan 17, 2020 12:10 pm

OK new day fresh eyes.

Today I tried to use wpa_cli to see if it would show me what's going on. When I try on another pi running buster (a pi zero W) I see:

Code: Select all

$ wpa_cli
wpa_cli v2.8-devel
Copyright (c) 2004-2019, Jouni Malinen <j@w1.fi> and contributors

This software may be distributed under the terms of the BSD license.
See README for more details.


Selected interface 'p2p-dev-wlan0'

Interactive mode

> 
and FWIW I also see:

Code: Select all

$ systemctl status wpa_supplicant.service 
● wpa_supplicant.service - WPA supplicant
   Loaded: loaded (/lib/systemd/system/wpa_supplicant.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2020-01-14 16:17:20 GMT; 2 days ago
 Main PID: 252 (wpa_supplicant)
   Memory: 2.7M
   CGroup: /system.slice/wpa_supplicant.service
           └─252 /sbin/wpa_supplicant -u -s -O /run/wpa_supplicant

Jan 14 16:17:18 PiZeroW systemd[1]: Starting WPA supplicant...
Jan 14 16:17:18 PiZeroW wpa_supplicant[252]: Successfully initialized wpa_supplicant
Jan 14 16:17:20 PiZeroW systemd[1]: Started WPA supplicant.
So I take it that's what's normal. But on the 3B+ with borked wifi I see essentially the same status of wpa_supplicant but wpa_cli is different:

Code: Select all

$ wpa_cli
wpa_cli v2.8-devel
Copyright (c) 2004-2019, Jouni Malinen <j@w1.fi> and contributors

This software may be distributed under the terms of the BSD license.
See README for more details.



Interactive mode

Could not connect to wpa_supplicant: (nil) - re-trying

and then it just hangs, until I CTRL-C out.

So there's a specific difference. If I can fix that problem maybe the wifi will sort itself out. :?

squirrelpie
Posts: 21
Joined: Fri Dec 13, 2019 8:49 pm

SOLVED: can't connect to new wifi repeater

Fri Jan 17, 2020 5:22 pm

Well, I eventually solved it.

Somehow, and I swear I didn't do it, /etc/resolv.conf had got rewritten. It contained just:

Code: Select all

nameserver 8.8.8.8
I put it back to the default contents, restarted dhcpcd and now I have my network connections back. :D

I'm somewhat puzzled and disappointed that there was nothing I saw in any logs or status output that gave me any hint of what was wrong. Just random poking about solved it.

Thanks for all the help, everybody :twisted:

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