doesn't scan for available wifi networks often enough + no way to manually force a scan

Bug #1491612 reported by teo1978 on 2015-09-02
This bug affects 12 people
Affects Status Importance Assigned to Milestone
One Hundred Papercuts
network-manager (Ubuntu)

Bug Description

Steps to reproduce:

- turn on a wifi router nearby
- click on the network applet icon

Expected behavior:
As soon as the new network becomes available, it should become visible in the list within few seconds (and if it is a network you have already configured and set to automatically connect to, it should connect)

Observed behavior:
You won't see the network show up in the list, or perhaps it will, after a few minutes. Way too much time.

Additionally, there should be an item in the menu such as "scan for networks now" to force scanning for available networks. But there's no such thing even.

So the only workaround is to physically disable and reenable wifi on hardware, if your computer has a button for that. That will trigger re-scanning for available networks.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: network-manager
ProcVersionSignature: Ubuntu 3.19.0-26.28-generic 3.19.8-ckt4
Uname: Linux 3.19.0-26-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.3
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Sep 2 23:48:42 2015
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2013-10-11 (691 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
 default via dev wlan0 proto static metric 1024 dev wlan0 scope link metric 1000 dev wlan0 proto kernel scope link src
SourcePackage: network-manager
UpgradeStatus: Upgraded to vivid on 2015-08-15 (18 days ago)
mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2015-02-20T16:52:59.722501
 wlan0 wifi connected /org/freedesktop/NetworkManager/Devices/2 Sixty-Seven 2dfa6e3a-076f-48f9-a40c-d182c47e4178 /org/freedesktop/NetworkManager/ActiveConnection/0
 43:29:1A:07:53:91 bt disconnected /org/freedesktop/NetworkManager/Devices/3 -- -- --
 eth0 ethernet unavailable /org/freedesktop/NetworkManager/Devices/1 -- -- --
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/0 -- -- --
nmcli-nm: Error: command ['nmcli', '-f', 'all', 'nm'] failed with exit code 2: Error: Object 'nm' is unknown, try 'nmcli help'.

Revision history for this message
teo1978 (teo8976) wrote :
Revision history for this message
Launchpad Janitor (janitor) wrote :

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

Changed in network-manager (Ubuntu):
status: New → Confirmed
Changed in network-manager (Ubuntu):
importance: Undecided → High
Changed in hundredpapercuts:
status: New → Confirmed
importance: Undecided → High
Revision history for this message
Andy Neitzke (neitzke) wrote :

I have this bug too, on Ubuntu 15.04, running on a Lenovo Thinkpad Yoga 12.

A workaround that works for me is to run "sudo iwlist scan". After the scan completes, the list of networks is updated in the network applet. But of course I agree that having to do this is irritating.

Revision history for this message
Brad Kowalczyk (brad-ibiscode) wrote :

This one has annoyed me for quite a while now (well before 15.x). Having to disable/enable wifi to get network manager applet to see the wifi ssid (or wait quit a while) is a bit of a pain and shouldn't be necessary for a modern OS. Also, the fact that there is no way anywhere, either in network-manager applet or in network manager itself (network settings), to force a refresh really sucks.

My network manager applet disappeared for a while (until I worked out how to fix that) so to get my lappy to see my wifi I had open Network Settings, click "Connect to a hidden network", then select the ssid from the drop down list of known networks. Not exactly convenient!

So a "scan now" button would be great, along with more frequent automatic wifi scanning.

Revision history for this message
RussianNeuroMancer (russianneuromancer) wrote :

I think do frequent automatic rescan could hurt battery life, so menu item for manual rescan would be better idea.

Revision history for this message
teo1978 (teo8976) wrote :

> I think do frequent automatic rescan could hurt battery life,
> so menu item for manual rescan would be better idea.

They don't need to be *very* frequent. Yes, the menu item for manual rescan is an absolute MUST (see below though), but it also has to rescan automatically from time to time.

Also note that the system knows when it's attached to power, and hence can scan more frequently in that case (assuming battery consumption really is affected).

Actually, when you manually unfold the network menu, *that* should already trigger a rescan (if the fact that it is scanning was indicated by an animation/icon, which it should, then there would be no need for a specific menu item), and also automatic rescan should be more frequent when the menu is unfolded. You aren't going to keep that menu open all the time anyway.

To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers