Ubuntu – How to change the refresh rate at which the network manager updates the wireless access points


Sometimes it takes too long for the network manager to update to see new wireless AP. Is it possible to change the time interval between checks?

Best Answer

The "refresh rate" (scan interval) is hardcoded in the source code of network manager. The interval is some value between 20 and 120 seconds. Some heuristics decide when to scan more often and when less often. There seems to be no way to configure the interval other than patching the source and compiling.

See the relevant source file of network manager version 0.9.0 and search for interval.

There is a lot of discussion on the internet about allowing users to change the interval. The developers do not want that. They argue that users might set the interval too low and that will cause grievance for all members of the wireless network, not only for the user alone.

I am sorry I cannot provide you a link to that discussion. I forgot to save the link and now I couldn't find it again. You will have to take my word for it.

So it is not possible to configure the refresh rates, and it seems that it will not happen anytime soon.

You can trigger a scan manually using the following command:

sudo iwlist eth1 scan

Replace eth1 with the name of your wireless device. Use iwconfig to find out the name of your wireless device.

You can list the found networks using nm-tool.

You can observe the activity of your wireless device using iwevent.