Timout during ifup with multiple WiFi interfaces on Kali Linux

Question

for my project I need two WiFi interfaces connected to a Raspberry Pi Zero W running Kali Linux (not Raspbian – anyway both are based on Debian). The onboard interface wlan0 shall not connect to any WiFi network (it is dedicated to scan the air in monitor mode). Instead I want another USB WiFi Adapter Edimax EW-7811Un to be used as interface wlan1 to connect to my home WiFi network.

My network interfaces configuration looks as simple as the following few lines:

auto lo
iface lo inet loopback

auto wlan0
iface wlan0 inet dhcp

auto wlan1
iface wlan1 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

Now the problem is, that the networking service fails to start with a timeout during boot time. See the service status:

Job for networking.service failed because a timeout was exceeded.
See "systemctl status networking.service" and "journalctl -xe" for details.
root@kali:~# cat networking-status.txt 
● networking.service - Raise network interfaces
     Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
     Active: failed (Result: timeout) since Mon 2020-05-11 10:40:47 CEST; 3min 17s ago
       Docs: man:interfaces(5)
    Process: 326 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=1/FAILURE)
   Main PID: 326 (code=exited, status=1/FAILURE)

May 11 10:40:44 kali wpa_supplicant[408]: Successfully initialized wpa_supplicant
May 11 10:40:47 kali wpa_supplicant[411]: wlan1: CTRL-EVENT-REGDOM-CHANGE init=USER type=COUNTRY alpha2=DE
May 11 10:40:47 kali systemd[1]: networking.service: start operation timed out. Terminating.
May 11 10:40:47 kali ifup[326]: Got signal Terminated, terminating...
May 11 10:40:47 kali ifup[326]: ifup: failed to bring up wlan1
May 11 10:40:47 kali wpa_supplicant[411]: nl80211: deinit ifname=wlan1 disabled_11b_rates=0
May 11 10:40:47 kali systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILURE
May 11 10:40:47 kali wpa_supplicant[411]: wlan1: CTRL-EVENT-TERMINATING
May 11 10:40:47 kali systemd[1]: networking.service: Failed with result 'timeout'.
May 11 10:40:47 kali systemd[1]: Failed to start Raise network interfaces.

I figured out, that I need to restart the networking service afterwards twice, to bring it finally up (obviously, this is a show stopper in a headless setup):

systemctl restart networking.service
systemctl restart networking.service

Unfortunately, I need to do that after each reboot, which is pretty annoying… So, my question is: Why does it come to a timeout during the networking service startup and how can I solve this?

Thanks in advance and
best regards

Answer 1

Upon writing my question, the answer came to me. I want to share it right away, so it shall help anyone else who stumbles over a similar issue.

First, I took a look at the networking service unit to get a clue, what it is doing, at all.

less /lib/systemd/system/networking.service

[Unit]
Description=Raise network interfaces
Documentation=man:interfaces(5)
DefaultDependencies=no
Requires=ifupdown-pre.service
Wants=network.target
After=local-fs.target network-pre.target apparmor.service systemd-sysctl.service systemd-modules-load.service ifupdown-pre.service
Before=network.target shutdown.target network-online.target
Conflicts=shutdown.target

[Install]
WantedBy=multi-user.target
WantedBy=network-online.target

[Service]
Type=oneshot
EnvironmentFile=-/etc/default/networking
ExecStart=/sbin/ifup -a --read-environment
ExecStop=/sbin/ifdown -a --read-environment --exclude=lo
RemainAfterExit=true
TimeoutStartSec=15

In the [Service] section I noticed the key value entry TimoutStartSec=15 -__-
So I just gave it a try and doubled the value to 30 seconds.

systemctl edit networking.service

The command above does not edit the original unit file located at /lib/systemd/system/networking.service. Instead it overrides just the lines you want within a newly created file located at /etc/systemd/system/networking.service.d/override.conf.

[Service]
TimeoutStartSec=30

And that was the trick! The WiFi interface wlan1 is now starting up successfully after each reboot.