Does not automatically reconnect to hidden WiFi network

Status changed to 'Confirmed' because the bug affects multiple users.

I have this issue on a Thinkpad with Xubuntu 15.04.
It seems not to be hardware-related.

The solution:
Uncomment the code which has been commented out due to an already fixed gnome bug. This fixed the issue for me. Please confirm that it does fix it for you, too.

michael@thinkpad:/etc$ git diff NetworkManager/dispatcher.d/01ifupdown
diff --git a/NetworkManager/dispatcher.d/01ifupdown b/NetworkManager/dispatcher.d/01ifupdown
index ebadfd1..f4de9cc 100755
--- a/NetworkManager/dispatcher.d/01ifupdown
+++ b/NetworkManager/dispatcher.d/01ifupdown
@@ -55,16 +55,16 @@ for i in $ADDRESS_FAMILIES; do
             ;;
 # pre-up/pre-down not implemented. See
 # https://bugzilla.gnome.org/show_bug.cgi?id=387832
-# pre-up)
-# export MODE="start"
-# export PHASE="pre-up"
-# run-parts /etc/network/if-pre-up.d
-# ;;
-# pre-down)
-# export MODE="stop"
-# export PHASE="pre-down"
-# run-parts /etc/network/if-down.d
-# ;;
+ pre-up)
+ export MODE="start"
+ export PHASE="pre-up"
+ run-parts /etc/network/if-pre-up.d
+ ;;
+ pre-down)
+ export MODE="stop"
+ export PHASE="pre-down"
+ run-parts /etc/network/if-down.d
+ ;;
         hostname|dhcp4-change|dhcp6-change)
             # Do nothing
             ;;
michael@thinkpad:/etc$

Created patch for the /etc/NetworkManager/dispatcher.d/01ifupdown script.

The patch works with Xubuntu 15.04, but the bug has been reported for Ubuntu 14.04.
Can someone confirm that the patch is sufficient to solve the issue on Ubuntu 14.04?
Probably the network-manager needs to be updated, too, if the version provided with Ubuntu 14.04 still lacks support for pre-up/pre-down (https://bugzilla.gnome.org/show_bug.cgi?id=387832).

The attachment "Patch for the /etc/NetworkManager/dispatcher.d/01ifupdown script" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

Unfortuately I have to admit that my patch did not really solve th issue.

While yesterday the problem did not reappear, today I was experiencing the problem again.

Before I was thinking, that the problem appeared everytime when the network was connected before and thus when not manually connecting on every second boot, but this might not be true, because yesterday I thought the issue was fixed, because the issue didn't appear after a reboot even when the network was connected before.

I was thinking, there was something like a state that survives a reboot and could be cleared with the patched script.
It might be that the patched script somehow changes some probabilities, but the issue is definitely not fixed.

When the issue occurs, the network manager tells me that there are wireless networks available, but it does not connect automatically to the hidden network.

Probably there is some state that is stored in NetworkManager:
* When you have manually disconnected from a wireless network, you probably don't want to reconnect automatically.
* When you was connected to a wireless network, you probably want to reconnect to that network.
* When you have manually chosen a specific network, you might want to connect only to that network

There should be something like on mobile phones where you can choose one network manually or let the phone choose the network automatically.

Maybe some of such state information survives a reboot.

Today I tried this:

michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[sudo] password for michael:
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/networking restart
[ ok ] Restarting networking (via systemctl): networking.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$

Restarting network-manager alone multiple times didn't lead to a wireless connection, but after networking restart and then network-manager restart the connect succeeded immediately.

Probably this gives a hint where to search for the issue.

To be sure, further tests are necessary, to be sure that this behaviour is reproducable.

Can someone confirm?

Now I have done further tests.
Sometimes calling network-manager restart once will suffice to get connected, but sometimes not. Then you can try again and again without getting a connection.
Then networking restart and then network-manager restart will do it.

michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[sudo] password for michael:
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$ sudo /etc/init.d/network restart
networking network-manager
michael@thinkpad:~$ sudo /etc/init.d/networking restart
[ ok ] Restarting networking (via systemctl): networking.service.
michael@thinkpad:~$ sudo /etc/init.d/network-manager restart
[ ok ] Restarting network-manager (via systemctl): network-manager.service.
michael@thinkpad:~$

Thus it seems that sometimes on a failed connect something gets broken so that it prevents you from getting a connection and that can be repaired by doing a networking restart.
I hope that this is useful to find the cause of this bug.

Next steps:
 - 1) Check the file /var/lib/NetworkManager/NetworkManager.state when the problem occurs next time.

With connected network it looks like:

[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true
WimaxEnabled=true

 - 2) Check the files in /var/lib/NetworkManager/ for their contents. Probably this might help to track down the problem.

Running Ubuntu Studio (Xubuntu) 14.04 I had this or a very similar problem when I changed name and hid the SSID on my wifi.

nm-manager kept looking for the old SSID and would not connect to the hidden network - I had to connect manually on boot.

When I told nm-manager to forget the old wifi the problem disappeared. My computer now connects to the hidden SSID and networking is OK.

I'm confirming this bug 6 years later is real and unfixed still! The solution worked for me. Can this be patched ASAP?

On the Debian bug site it shows that adding wifi.hidden yes via "nmcli connection modify XXXX wifi.hidden yes" does seem to produce a solution but it only works one time. When I did this and restarted network manager service I had hidden wifi connect once successfully but it wouldn't do it again when I cycled the wifi interface down/up.

I have never had this problem on the same laptop (asus f550l) with every LTS from 14.04 but it appears with 20.04

Could someone having the issue report directly upstream to https://gitlab.freedesktop.org/NetworkManager/NetworkManager/issues/ ?