Please note this question is not a duplicate of How do I get a Realtek RTL8723BE wireless card to work?
In that question, the user is able to get connections to wireless networks and they get dropped intermittently. In my situation, Ubuntu does not list any wireless networks to connect. Also, if you read the comments section of this question, you will find that workaround mentioned in the duplicate question has already been tried and that did not help.
Here is what was tried from answer in the duplicate question: Downloaded rtlwifi and dkms pkg suggested by the duplicate question and successfully ran 'sudo dpkg -i dkms_2.2.0.3-2ubuntu11_all.deb rtlwifi-new-dkms_0.10_all.deb'. Rebooted and find that the wireless device wlp2s0 no longer found when running 'ifconfig'. Also, wifi option in top right of the screen is no longer available. Since my situation got worse, removed the dkms package and my wlp2s0 returned but still no wireless connection.
I have Ubuntu Xenial(16.04.2) installed and unable to find wireless networks to connect to. Wireless switch is on and wireless networking is enabled and the device is in a up state
wlp2s0 Link encap:Ethernet HWaddr 94:53:30:4d:84:27
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
More information on my setup:
$ lspci -nn | grep 0280
02:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723]
$ lsusb
Bus 001 Device 004: ID 046d:c52f Logitech, Inc. Unifying Receiver
Bus 001 Device 003: ID 05c8:0383 Cheng Uei Precision Industry Co., Ltd (Foxlink)
Bus 001 Device 002: ID 0438:7900 Advanced Micro Devices, Inc.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 002: ID 0bda:b006 Realtek Semiconductor Corp.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ rfkill list all
0: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
$ dmesg | grep -e wlan -e b43
[ 15.006188] rtl8723be 0000:02:00.0 wlp2s0: renamed from wlan0
$ sudo modprobe b43
$
This is a dual boot system and when I boot with Windows 10, I am able to find wireless networks and connect successfully with the same hardware.
Tried workaround mentioned in here but did not help.
Ubuntu is able to find wireless connection at home without any problem. When I go to a library, that's when Ubuntu fails to pick up any wireless network.
Rebooted Ubuntu and captured syslog messages when I was in a library. Here are messages I see in the syslog that seemed relevant to me to debug the probem:
Feb 20 09:56:52 voyager kernel: [ 14.026332] rtl8723be 0000:02:00.0:
enabling device (0000 -> 0003) Feb 20 09:56:52 voyager kernel: [
14.051292] rtl8723be: Using firmware rtlwifi /rtl8723befw.bin Feb 20 09:56:52 voyager kernel: [ 14.084384] ieee80211 phy0: Selected rate
con trol algorithm 'rtl_rc' Feb 20 09:56:52 voyager kernel: [
14.084789] rtlwifi: rtlwifi: wireless switch is on Feb 20 09:56:52 voyager kernel: [ 14.086744] rtl8723be 0000:02:00.0 wlp2s0: re named
from wlan0 .... Feb 20 09:56:54 voyager NetworkManager[794]: <info>
[1487602614.9362] NetworkMa nager (version 1.2.2) is starting... Feb
20 09:56:54 voyager NetworkManager[794]: <info> [1487602614.9365]
Read conf ig: /etc/NetworkManager/NetworkManager.conf (etc:
default-wifi-powersave-on.conf ) Feb 20 09:56:55 voyager
thermald[820]: Unsupported cpu model, use thermal-conf.x ml file or
run with --ignore-cpuid-check Feb 20 09:56:55 voyager thermald[820]:
THD engine start failed Feb 20 09:56:55 voyager NetworkManager[794]:
<info> [1487602615.1807] manager[0 x26811a0]: monitoring kernel
firmware directory '/lib/firmware'. Feb 20 09:56:55 voyager
NetworkManager[794]: <info> [1487602615.1808] monitorin g ifupdown
state file '/run/network/ifstate'. Feb 20 09:56:55 voyager
NetworkManager[794]: <info> [1487602615.3325] dns-mgr[0 x26930b0]:
set resolv-conf-mode: dnsmasq, plugin="dnsmasq" Feb 20 09:56:55
voyager NetworkManager[794]: <info> [1487602615.3326] dns-mgr[0
x26930b0]: using resolv.conf manager 'resolvconf' Feb 20 09:56:55
voyager NetworkManager[794]: <info> [1487602615.4015] rfkill1: found
WiFi radio killswitch (at
/sys/devices/pci0000:00/0000:00:02.3/0000:02:00.
0/ieee80211/phy0/rfkill1) (driver rtl8723be) Feb 20 09:56:55 voyager
systemd[1]: Started Network Manager. Feb 20 09:56:55 voyager
systemd[1]: Starting Network Manager Wait Online... Feb 20 09:56:55
voyager systemd[1]: Reached target Network. Feb 20 09:56:55 voyager
dbus[748]: [system] Activating via systemd: service name
='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.servic e' Feb 20 09:56:55
voyager systemd[1]: Starting Network Manager Script Dispatcher S
ervice... Feb 20 09:56:55 voyager ModemManager[795]: <info> Couldn't
find support for dev ice at
'/sys/devices/pci0000:00/0000:00:02.2/0000:01:00.0': not supported by
any plugin Feb 20 09:56:55 voyager ModemManager[795]: <info>
Couldn't find support for dev ice at
'/sys/devices/pci0000:00/0000:00:02.3/0000:02:00.0': not supported by
any plugin ... Feb 20 09:56:55 voyager NetworkManager[794]: <info>
[1487602615.8595] init! Feb 20 09:56:55 voyager NetworkManager[794]:
<info> [1487602615.8600] managemen t mode: unmanaged Feb 20 09:56:55
voyager NetworkManager[794]: <info> [1487602615.8608] devices a dded
(path: /sys/devices/pci0000:00/0000:00:02.2/0000:01:00.0/net/enp1s0,
iface: enp1s0) Feb 20 09:56:55 voyager NetworkManager[794]: <info>
[1487602615.8608] device ad ded (path:
/sys/devices/pci0000:00/0000:00:02.2/0000:01:00.0/net/enp1s0, iface:
enp1s0): no ifupdown configuration found. Feb 20 09:56:55 voyager
NetworkManager[794]: <info> [1487602615.8609] devices a dded (path:
/sys/devices/pci0000:00/0000:00:02.3/0000:02:00.0/net/wlp2s0, iface:
wlp2s0) Feb 20 09:56:55 voyager NetworkManager[794]: <info>
[1487602615.8609] device ad ded (path:
/sys/devices/pci0000:00/0000:00:02.3/0000:02:00.0/net/wlp2s0, iface:
wlp2s0): no ifupdown configuration found. Feb 20 09:56:55 voyager
NetworkManager[794]: <info> [1487602615.8609] devices a dded (path:
/sys/devices/virtual/net/lo, iface: lo) Feb 20 09:56:55 voyager
NetworkManager[794]: <info> [1487602615.8609] device ad ded (path:
/sys/devices/virtual/net/lo, iface: lo): no ifupdown configuration fo
und. Feb 20 09:56:55 voyager NetworkManager[794]: <info>
[1487602615.8609] end _init . Feb 20 09:56:55 voyager
NetworkManager[794]: <info> [1487602615.8610] settings: loaded
plugin ifupdown: (C) 2008 Canonical Ltd. To report bugs please use
the NetworkManager mailing list.
(/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-set
tings-plugin-ifupdown.so) Feb 20 09:56:55 voyager NetworkManager[794]:
<info> [1487602615.8615] SettingsP lugin-Ofono: init! Feb 20 09:56:55
voyager NetworkManager[794]: <warn> [1487602615.8616] SettingsP
lugin-Ofono: file doesn't exist: /var/lib/ofono Feb 20 09:56:55
voyager NetworkManager[794]: <info> [1487602615.8616] SettingsP
lugin-Ofono: end _init. Feb 20 09:56:55 voyager NetworkManager[794]:
<info> [1487602615.8616] settings: loaded plugin ofono: (C)
2013-2016 Canonical Ltd. To report bugs please use th e
NetworkManager mailing list.
(/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-s
ettings-plugin-ofono.so) Feb 20 09:56:55 voyager NetworkManager[794]:
<info> [1487602615.8616] (40512336 ) ... get_connections. Feb 20
09:56:55 voyager NetworkManager[794]: <info> [1487602615.8617]
(40512336 ) ... get_connections (managed=false): return empty list.
Full part of syslog messages is available here
sudo apt purge rtlwifi-new-dkms.