TL;DR: wavemon does not work, iwconfig works fine.


I don't seem to get any results from wavemon, although it sees the right interface.

If I start wavemon

$ sudo wavemon

it shows for Interface:

wlan0 (IEEE 802.11bgn), phy 0, reg: n/a

After the dynamic info update interval, it adds some info on WPA/WPA2:

wlan0 (IEEE 802.11bgn, WPA/WPA2), phy 0, reg: n/a

Also, it sees my Network: wlan0 (UP RUNNING BROADCAST MULTICAST), mac address, qlen (1000), ip and mtu.

However, in the Levels panel, it just says


The Scan window (F3) says:

Scan trigger failed on wlan0: No such device

And I have no statistics.


I found this question, but it does not solve my problem for two reasons: 1) I already started wavemon as sudo and 2) I can use iwconfig just fine. It says:

$ sudo iwconfig wlan0
[sudo] password for mk:
wlan0     IEEE 802.11bgn  ESSID:"<my essid>"  Nickname:"rtl_wifi"
          Mode:Managed  Frequency:2.462 GHz  Access Point: 01:23:45:67:89:ab
          Bit Rate:72 Mb/s   Sensitivity:0/0
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:****-****-****-****-****-****-****-****   Security mode:open
          Power Management:off
          Link Quality=97/100  Signal level=61/100  Noise level=0/100
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

(ESSID and Access Point censored)

I also read under Dependencies on the github source page README.md something about CONFIG_CFG80211_WEXT. However, I read somewhere else that also iwconfig should depend on this. Therefore, I expect it is no solution for me.


I am on Ubuntu 16.04.2 LTS with LXDE and use wavemon 0.8.0 with ncurses 6.0.20160213. The USB WLAN adapter is a 0bda:8172 Realtek Semiconductor Corp. RTL8191SU 802.11n (taken from lsusb). Its configuration (from sudo lshw -class network) is broadcast=yes driver=r8712u ip= multicast=yes wireless=IEEE 802.11bgn

After installing wavemon, I have rebooted the system.

From dmesg | grep -i firmware I read one related line:

[   16.880896] usb 1-5: r8712u: Loading firmware from "rtlwifi/rtl8712u.bin"

The network is managed by NetworkManager v1.2.6.

Happy to provide more info where needed (but where to start?)

What I would ultimately want, is diagnose my situation where WiFi is sometimes fast (at least, reasonable as expected, topping at 10Mb/s) and sometimes VERY slow, often reconnecting. I am two floors up (with one layer of enforced concrete) from the router, a WRT160NL, sending wireless-N only. The antennae are pointer sideways to maximize throughput, as is the antenna of the adapter. I expect the distance to be a possible cause, although iwconfig and /proc/net/wireless usually report a link quality of 90-100/100 and a signal level of ~70/100. I'd like to look into this a bit further.

1 Answer 1


Does iw dev wlan0 scan produce any result? If not then it seems your driver does not support the new wireless networking API. Try an older version of wavemon v0.7.6


  • 1
    Installing an older version from pkgs.org (the one from Ubuntu 14.04) actually worked. Wavemon is now running as expected. Dec 31, 2018 at 8:59

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