Setup: rasbian raspberry pi 4.4.14-v7+ with systemd for network related stuff.
Using the internal broadcom wifi
Access Point: Another RPi3 with Hostapd 1:2.3-1+deb8u3 and 4.4.14-v7+
I will refer to "client" as the RPI which is trying to connect to the Hostapd Access Point (WPA2)
The Hostapd uses an isc-dhcp-server on the wifi interface which works fine (sends leases, renews them, DHCPACK etc..)
Requirement:
I am unable to accept the fallback mode via /etc/network/interfaces or similiar setups via f.e. ifplugd, which rely on that file.
Currently we use dhclient instead of the default dhcpcd.
Out of the questions are other network managers as well as any graphical tools.
Problems:
The client needs a full reboot to have wifi working again if the Access Point is not reachable for a short time (reboot, power loss, something like that)
i am not connected to the AP via wpa_supplicant at that point. (hostapd_cli all_sta does not show my Wifi MAC of the client)
iwconfig wlan0
wlan0 IEEE 802.11bgn ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=31 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
The "old" version of solving this is either via ifplugd scripts (ifup/ifdown actions) and/or having set wpa-roam in /etc/network/interfaces and using the compatibility layer "networking.service - LSB: Raise network interfaces."
Another option would be to use a cronjob to detect the failing connection and restart $SOMETHING.
Sadly i was unable to figure out what that $SOMETHING is.
As i only want to use the systemd-network way i did not load the "networking" unit.
It seems to me that wpa_supplicant does try to scan for the AP again, but somehow rejects the matching AP SSID.
Here are the settings.
loaded services:
systemctl -t service
UNIT LOAD ACTIVE SUB DESCRIPTION
bluetooth.service loaded active running Bluetooth service
console-setup.service loaded active exited LSB: Set console font and keymap
cron.service loaded active running Regular background program processing daemon
dbus.service loaded active running D-Bus System Message Bus
dphys-swapfile.service loaded active exited LSB: Autogenerate and use a swap file
fake-hwclock.service loaded active exited Restore / save the current clock
getty@tty1.service loaded active running Getty on tty1
hciuart.service loaded active running Configure Bluetooth Modems connected by UART
hdparm.service loaded active exited LSB: Tune IDE hard disks
kbd.service loaded active exited LSB: Prepare console
keyboard-setup.service loaded active exited LSB: Set preliminary keymap
kmod-static-nodes.service loaded active exited Create list of required static device nodes for the current kernel
network-wireless@wlan0.service loaded active exited Wireless network connectivity (wlan0)
ntp.service loaded active running LSB: Start NTP daemon
openvpn.service loaded active exited OpenVPN service
postfix.service loaded active running LSB: Postfix Mail Transport Agent
raspi-config.service loaded active exited LSB: Switch to ondemand cpu governor (unless shift key is pressed)
rc-local.service loaded active running /etc/rc.local Compatibility
rsyslog.service loaded active running System Logging Service
ssh.service loaded active running OpenBSD Secure Shell server
systemd-fsck-root.service loaded active exited File System Check on Root Device
systemd-fsck@dev-mmcblk0p1.service loaded active exited File System Check on /dev/mmcblk0p1
systemd-journald.service loaded active running Journal Service
systemd-logind.service loaded active running Login Service
systemd-modules-load.service loaded active exited Load Kernel Modules
systemd-networkd.service loaded active running Network Service
systemd-random-seed.service loaded active exited Load/Save Random Seed
systemd-remount-fs.service loaded active exited Remount Root and Kernel File Systems
systemd-rfkill@rfkill0.service loaded active exited Load/Save RF Kill Switch Status of rfkill0
systemd-rfkill@rfkill1.service loaded active exited Load/Save RF Kill Switch Status of rfkill1
systemd-setup-dgram-qlen.service loaded active exited Increase datagram queue length
systemd-sysctl.service loaded active exited Apply Kernel Variables
systemd-tmpfiles-setup-dev.service loaded active exited Create Static Device Nodes in /dev
systemd-tmpfiles-setup.service loaded active exited Create Volatile Files and Directories
systemd-udev-trigger.service loaded active exited udev Coldplug all Devices
systemd-udevd.service loaded active running udev Kernel Device Manager
systemd-update-utmp.service loaded active exited Update UTMP about System Boot/Shutdown
systemd-user-sessions.service loaded active exited Permit User Sessions
triggerhappy.service loaded active running LSB: triggerhappy hotkey daemon
udev-finish.service loaded active exited Copy rules generated while the root was ro
user@0.service loaded active running User Manager for UID 0
cat /etc/systemd/network/00-wireless.network
#General configuration wlan0
[Match]
Name=wlan0
[Network]
DHCP=ipv4
i did set some additional debug info in /var/log/wpa_supplicant.log so th ExecStart is a bit longer than usual.
cat /etc/systemd/system/network-wireless@.service
[Unit]
Description=Wireless network connectivity (%i)
Wants=network.target
Before=network.target
BindsTo=sys-subsystem-net-devices-%i.device
After=sys-subsystem-net-devices-%i.device
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/sbin/ip l set %i up
ExecStart=/sbin/wpa_supplicant -t -dd -f /var/log/wpa_supplicant.log -dd -B -i %i -c /etc/wpa_supplicant/wpa_supplicant.conf
ExecStart=/sbin/dhclient %i
ExecStop=/sbin/ip l set %i down
[Install]
WantedBy=multi-user.target
cat /etc/wpa_supplicant/wpa_supplicant.conf
country=DE
ctrl_interface=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="testap"
psk="testconn"
}
some logs:
booting the client:
systemctl status network-wireless@wlan0.service
● network-wireless@wlan0.service - Wireless network connectivity (wlan0)
Loaded: loaded (/etc/systemd/system/network-wireless@.service; enabled)
Active: active (exited) since Fri 2016-08-05 12:21:17 CEST; 3min 32s ago
Process: 431 ExecStart=/sbin/dhclient %i (code=exited, status=0/SUCCESS)
Process: 425 ExecStart=/sbin/wpa_supplicant -t -dd -f /var/log/wpa_supplicant.log -dd -B -i %i -c /etc/wpa_supplicant/wpa_supplicant.conf (code=exited, status=0/SUCCESS)
Process: 387 ExecStart=/sbin/ip l set %i up (code=exited, status=0/SUCCESS)
Main PID: 431 (code=exited, status=0/SUCCESS)
booting client (everything OK, connection stable and working for hours/days on previous tests)
journalctl -u network-wireless@wlan0.service -b
-- Logs begin at Fri 2016-08-05 12:21:05 CEST, end at Fri 2016-08-05 12:22:53 CEST. --
Aug 05 12:21:08 testclient systemd[1]: Starting Wireless network connectivity (wlan0)...
Aug 05 12:21:09 testclient dhclient[431]: DHCPREQUEST on wlan0 to 255.255.255.255 port 67
Aug 05 12:21:13 testclient dhclient[431]: DHCPREQUEST on wlan0 to 255.255.255.255 port 67
Aug 05 12:21:17 testclient dhclient[431]: DHCPREQUEST on wlan0 to 255.255.255.255 port 67
Aug 05 12:21:17 testclient dhclient[431]: DHCPACK from 192.168.100.1
Aug 05 12:21:17 testclient dhclient[431]: bound to 192.168.100.11 -- renewal in 60 seconds.
Aug 05 12:21:17 testclient systemd[1]: Started Wireless network connectivity (wlan0).
Aug 05 12:22:17 testclient dhclient[549]: DHCPREQUEST on wlan0 to 192.168.100.1 port 67
Aug 05 12:22:17 testclient dhclient[549]: DHCPACK from 192.168.100.1
Aug 05 12:22:17 testclient dhclient[549]: bound to 192.168.100.11 -- renewal in 53 seconds.
rebooting the AP:
Aug 5 12:26:55 testclient systemd-networkd[422]: wlan0 : lost carrier
Aug 5 12:26:55 testclient dhclient: DHCPREQUEST on wlan0 to 192.168.100.1 port 67
Aug 5 12:27:00 testclient dhclient: DHCPREQUEST on wlan0 to 192.168.100.1 port 67
Aug 5 12:27:12 testclient dhclient: DHCPREQUEST on wlan0 to 192.168.100.1 port 67
Aug 5 12:27:32 testclient dhclient: DHCPREQUEST on wlan0 to 192.168.100.1 port 67
this leads me to believe that i am missing an option on "lost carrier" in the systemd-network unit to restart the wireless service.
What part did i miss or where can i get more info if my search skills on SE and google did fail me. Thanks.
note: according to the raspberrypi.se help i should not use the rpi se site but UX, which i did. Please move if i misunderstood the part of "Questions directly related to Linux/Unix issues. Please use the Unix & Linux Exchange. "
multiple references i tried, however most of them are either outdate or did not help me in my situation.
https://raspberrypi.stackexchange.com/questions/4120/how-to-automatically-reconnect-wifi https://wiki.archlinux.org/index.php/WPA_supplicant
http://weworkweplay.com/play/automatically-connect-a-raspberry-pi-to-a-wifi-network/
Auto reconnect to wifi once disconnected?
