Sometimes (particularly lately) I encounter the issue detailed below. All the devices are accounted for, detected, and acknowledged by the system. I've been able to verify this using every method I can think of, including digging through system directories & files like /sys/kernel/debug/usb/devices, cross-referencing common tools like lshw, lspci, lsusb, etc. Any idea what's going on, and/or why? Cheers.root@main:~# service networking startJob for networking.service failed because the control process exited with error code.See systemctl status networking.service and journalctl  -xe for details.root@main:~# systemctl status networking.service networking.service - Raise network interfaces   Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)   Active: failed (Result: exit-code) since Sat 2017-08-12 12:18:03 AWST; 2min 48s ago     Docs: man:interfaces(5)  Process: 30803 ExecStart=/sbin/ifup -a --read-environment (code=exited, status=1/FAILURE)  Process: 30800 ExecStartPre=/bin/sh -c [ $CONFIGURE_INTERFACES != no ] && [ -n $(ifquery --read-environment --list --exclude=lo) ] && udevadm settle (code=exited, status=0/SUCCESS) Main PID: 30803 (code=exited, status=1/FAILURE)Aug 12 12:18:03 main systemd[1]: Starting Raise network interfaces...Aug 12 12:18:03 main ifup[30803]: Cannot find device wlan2Aug 12 12:18:03 main ifup[30803]: ifup: failed to bring up wlan2Aug 12 12:18:03 main systemd[1]: networking.service: Main process exited, code=exited, status=1/FAILUREAug 12 12:18:03 main systemd[1]: Failed to start Raise network interfaces.Aug 12 12:18:03 main systemd[1]: networking.service: Unit entered failed state.Aug 12 12:18:03 main systemd[1]: networking.service: Failed with result 'exit-code'.
Unable to raise WLAN interface or start networking service
networking;systemd;network interface;services;wlan