ifup command fails

[test-men]

Hello. Ask questions about the ifup command. I'm sorry if it's a weird question. If you know anything, please let me know.

I modified the following files and run sudo ifup --force wlan0.
/etc/network/interfaces

Then, the following error occurs and wireless connection fails.

wpa_supplicant: /sbin/wpa_supplicant daemon failed to start
run-parts: /etc/network/if-pre-up.d/wpasupplicant exited with return code 1
Failed to bring up wlan0.

I investigated. I found that if you execute killall wpa_suppulicant once, you can use ifup command.

I'm using debian 10.4. Do I have to killall every time I boot?

Also, the killall command is not supported in Debian 10.4. (Maybe) I think it was supported by default in Debian 9.6. Is the killall command no supported by default?

[LE_746F6D617A7A69]

First of all, ifup/down and ifconfig are deprecated if favor of ip.

To bring up the interface You should use:

Code: Select all

ip link set <interface> up #or down, to disable it

Another problem is that the interface name wlan0 is no longer used (by default).
To list available interfaces use:

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ip link show

Wireless interface names are starting with 'wl'

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Yes, killall is not installed by default, which is strange, because the psmisc package contains also other very useful tools, like pstree - somehow I can't believe that this decision was taken based on popcon stats...

[Head_on_a_Stick]

First of all, ifup/down and ifconfig are deprecated if favor of ip.

Although it is true that ip has replaced ifconfig it is most certainly *not* a replacement for ifupdown — the ip command cannot associate with wireless networks at all, unlike ifupdown. The ifupdown utility is alive and well and will continue to be supported in Debian for the foreseeable future.

I modified the following files and run sudo ifup --force wlan0.
/etc/network/interfaces

Then, the following error occurs and wireless connection fails.

Code: Select all

wpa_supplicant: /sbin/wpa_supplicant daemon failed to start
run-parts: /etc/network/if-pre-up.d/wpasupplicant exited with return code 1
Failed to bring up wlan0.

Looks like the /etc/network/if-pre-up.d/wpasupplicant script is broken.

Please post the full output of

Code: Select all

grep -vR '^#\|^$' /etc/network

[LE_746F6D617A7A69]

First of all, ifup/down and ifconfig are deprecated if favor of ip.

Although it is true that ip has replaced ifconfig it is most certainly *not* a replacement for ifupdown — the ip command cannot associate with wireless networks at all, unlike ifupdown. The ifupdown utility is alive and well and will continue to be supported in Debian for the foreseeable future.

It is a replacement for ifup/down - You can create tunnels, bridges, etc with a single command - but You are right - it can't replace ifup/down in case of standard wifi networks - my bad, sorry for posting misleading information ...