"sudo ifup wlan0" shows "unknown interface wlan0"

[Shahriar Al Rabbi]

"sudo ifup wlan0" shows "unknown interface wlan0"
In the desktop, the internet connectivity logo, ethernet works fine but shows "no wireless device detected.
I installed the April 2018 raspbian stretch properly and still doesn't work.

If there is a solution, please let me know.
Or the product might have been damaged before it came to me.

"ifconfig" shows "eth0", "lo" as well as "wlan0" .
So, there might be a solution.

[copperly]

I second that motion

[mahjongg]

Split off from topic marked [SOLVED]

[MrEngman]

Try these

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sudo ip link set wlan0 down
sudo ip link set wlan0 up

[PeterO]

Try running "ifconfig" to see
a) if the interfaces exist
b) What they are called.

PeterO

[Cowpoke]

Finally, are the ifup and ifdown commands obsolete?

[SurferTim]

Finally, are the ifup and ifdown commands obsolete?

Yes.

[rohtua]

Hi, I had some similar problems a while ago on a fresh raspbian install I think what sorted it for me in the end was the Wi-Fi localisation options in raspi-config, when I looked I'd set the timezone options but now you get separate options for setting your Wi-Fi country. Might not do a lot but if I remember rightly it did help with the issues I was having at the time.

[HermannSW]

Try these

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sudo ip link set wlan0 down
sudo ip link set wlan0 up

Thank you, that worked for me while ifup did not.

Pi ZeroW was connected to ESP-01s module access point. For some reason the connection dropped and "ip link show" showed wlan0 in DORMANT state. First I tried only your 2nd command, that did not help. But running both did work!

[OutsourcedGuru]

If both ifup and ifdown are now obsolete, you might consider removing their respective man pages and executables so that you don't fool someone like myself. As it is, the command is present and indicates:

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ifup: unknown interface wlan0

...rather than the expected:

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sudo: ifup: command not found

[rpdom]

If both ifup and ifdown are now obsolete, you might consider removing their respective man pages and executables so that you don't fool someone like myself.

The proper way to do that would be to remove the ifupdown package. I'm not sure why it is still installed. Perhaps something in it is still required?

[SageDesign]

I am trying to build a cluster of 5 Pis, 3 x 3B+ and 2 x Pi4, using a SKY SR102 wireless router to connect them. Not going smoothly: the 3Bs are happy and connect, but the 2 x 4s will not connect, even though their setups appear to be identical. I cannot persuade them to connect, using ifup (?) or "set wlan0 up". They will occasionally connect, for no known reason. Any ideas please?