How to connect to wifi from the terminal?

[je55eah]

I attempted to uninstall openbox and jwm because I am trying to replace the window manager. I'll be posting about that soon because it isn't going too well.

What is the best way to connect to wifi from the terminal? I attempted to use nmtui after installing network-manager but the wifi is not listed.

I experimented with adding

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auto wlan0
iface wlan0 inet dhcp

to /etc/network/interfaces
and the wifi did appear in nmtui once after I removed those lines and restarted the network manager service, but I haven't been able to repeat it so I don't know why it worked the one time. Is there a better tool already installed or a reliable way to set the system up to automatically connect to a preferred network and fallback to other know networks in a logical way?

[Trapster]

I've had good luck with wicd in Debiandog-Jessie

https://wiki.debian.org/WiFi/HowToUse#Wicd

[je55eah]

Thanks Trapster.

Rather than installing depreciated software I worked out a way to do it with the preinstalled packages.

Method 1 (open network):

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cat > /etc/wpa_supplicant/wpa_supplicant.conf << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
    ssid="Channel2B"
    key_mgmt=NONE
}
EOF

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

Method 1 (cleartext password):

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cat > /etc/wpa_supplicant/wpa_supplicant.conf << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
    ssid="Channel2B"
    psk="password"
}
EOF

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

Method 1 (hashed password):

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echo -n password | iconv -t utf16le | openssl md4

use the hash below

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cat > /etc/wpa_supplicant/wpa_supplicant.conf << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
    ssid="Channel2B"
    password=hash:hash_from_above
}
EOF

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

Method 1 (alternative hashed password):

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wpa_passphrase "Channel2B" password

that will produce output like:

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network={
	ssid="Channel2B"
	#psk="password"
	psk=1b964719888513fdebf19047efdf4b6f182eef9d2d58639eb9e25f437cd30da8
}

remove the line with your password so you get

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network={
	ssid="Channel2B"
	psk=1b964719888513fdebf19047efdf4b6f182eef9d2d58639eb9e25f437cd30da8
}

then use that stanza below

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cat > /etc/wpa_supplicant/wpa_supplicant.conf << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
	ssid="Channel2B"
	psk=1b964719888513fdebf19047efdf4b6f182eef9d2d58639eb9e25f437cd30da8
}
EOF

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

the line that reads
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
could also simply be
ctrl_interface=/run/wpa_supplicant

Method 2 (open network)

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cat > /etc/wpa_supplicant/wpa_supplicant.conf << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US
EOF

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

wpa_cli scan
wpa_cli scan_results
wpa_cli add_network
wpa_cli set_network 0 ssid '"Channel2B"'
wpa_cli set_network 0 key_mgmt NONE

wpa_cli enable_network 0

#optional
wpa_cli save_config

ip a

Method 2 (cleartext password)

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cat > /etc/wpa_supplicant/wpa_supplicant.conf << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US
EOF

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

wpa_cli scan
wpa_cli scan_results
wpa_cli add_network
wpa_cli set_network 0 ssid '"Channel2B"'
wpa_cli set_network 0 psk '"password"'

wpa_cli enable_network 0

#optional
wpa_cli save_config

ip a

Method 2 (hashed password)

Generate your hash with one of the methods used above in method 1 then use it instead of the password.

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cat > /etc/wpa_supplicant/wpa_supplicant.conf << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US
EOF

wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

wpa_cli scan
wpa_cli scan_results
wpa_cli add_network
wpa_cli set_network 0 ssid '"Channel2B"'
wpa_cli set_network 0 psk '"password_hash"'

wpa_cli enable_network 0

#optional
wpa_cli save_config

ip a

When the config is saved then Method 2 can be started after a reboot with

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wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf
wpa_cli enable_network 0

I didn't fully test every option, but I tested a lot of them to the point where it was working for me.

You can create a shell script to run any of these by starting the file with #!/bin/sh

[je55eah]

Additionally,

With either method you can add the pertinent commands to /etc/profile to automatically connect at startup.

The built in startup process also tries to connect and you will see that it reports a failure with method 1 and it tries but fails to call ifup with method 2. Neither results in an automatic start. I attempted to tap into that and get it to start the wifi as someone must have intended, but I failed. Oddly, I did discover that if you add something to /etc/network/interfaces such as

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wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

The startup script reports an error but the wifi is actually connected... If you just want the result and you don't care if the path to it is broken and poorly understood then that is one solution.

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iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

also works and it fails with a green error instead of a red one.

If someone can explain the right way to hook into this I'd appreciate it. Without better documentation, the best solution is probably just to initialize wifi with /etc/profile.

[gumanzoy]

I use nmcli:

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nmcli d wifi connect WIFISSID password WIFIPASS