Unable to get the specific AP info via "iwlist wlan0 scanning"

[nakoruru]

Hi, i have a router with wireless on,and i want to get the ap information via "iwlist wlan0 scanning",but seems the scan result does't contain the ap info i want. meanwhile, the cell phone can get the router ap info, does anyone encounter same questions? and how to resolve? i try to reboot the PC or router, but it doesn't work.

[nakoruru]

i got some new informations. but also got some new questions.

1.when the ap is in the 13 frequency band, i can't get the ap info via iwlist scanning. which is very weird.

2.Given that the i get the ap info of my router which is in frequency band 1, then i change the router to frequency band 13, but when i execute "iwlist wlan0 scanning" , i still find that the ap is in frequency 1. i guess the wifi doesn't "really" scan the ap around but instead,it just get the result from cache, if it's true, how to clean the cache and make the wifi do a "real" scanning.

[grahammechanical]

What particular information are you seeking? Are you looking for information about your own setup or about nearby wireless Access Points?

Check out the Wireless Trouble Shooting Guide at

https://help.unbuntu.com/community/WifiDocs/WirelessTroubleShootingGuide

Regards

[nakoruru]

thanks for your reply, i am seeking for the information about my own wireless setup to sovle the 2 weird issue:
1. unable to get the nearby ap info which is in 13 frequency band.
2. when a nearby ap change it's frequency band from other to 13, the ap is still found in it's original band by executing"iwlist scanning ", but actually unable to connect.

[chili555]

i guess the wifi doesn't "really" scan the ap around but instead,it just get the result from cache, if it's true, how to clean the cache and make the wifi do a "real" scanning.

Here is a quote from man iwlist:

Triggering scanning is a privileged operation (root only) and normal users can only read left-over scan results.

The short answer is:

sudo iwlist wlan0 scan

[nakoruru]

thanks chili555^^, but i do run the command as root, so i guess i actually get the latest ap info, and i also try "sudo iwlist wlan0 scanning", but get the same result.

below is the detailed phenomenon:

first,i change the router to frequency band 6 (namely channel 6), and my wifi can find it and show that it is in frequency band 6, now i change the router to band 13(or 12), my wifi still find it , but it show that the route ap is still in band 6, this should be wrong. and after a period of time, the route ap info disappeared.
if i change the route to other band such as 1,or 9, wifi can discover the change immediately.

so i conclude that the wifi i used is unable to detect the ap info which in frequency band 12,13, and the wifi doesn't clean the ap info which is already unavailable in times.

any advices? thanks^^