Por si sirve de ayuda:
alejam14@alejam14-Satellite-L500:~$ sudo airmon-ng start wlan0
[sudo] password for alejam14:
Found 5 processes that could cause trouble.
If airodump-ng, aireplay-ng or airtun-ng stops working after
a short period of time, you may want to kill (some of) them!
PID Name
875 avahi-daemon
876 NetworkManager
878 avahi-daemon
959 wpa_supplicant
1714 dhclient
Process with PID 1714 (dhclient) is running on interface wlan0
Interface Chipset Driver
wlan0 Unknown rtl819xSE (monitor mode enabled)
alejam14@alejam14-Satellite-L500:~$ sudo airmon-ng start wlan0
[sudo] password for alejam14:
Found 5 processes that could cause trouble.
If airodump-ng, aireplay-ng or airtun-ng stops working after
a short period of time, you may want to kill (some of) them!
PID Name
875 avahi-daemon
876 NetworkManager
878 avahi-daemon
959 wpa_supplicant
1714 dhclient
Process with PID 1714 (dhclient) is running on interface wlan0
Interface Chipset Driver
wlan0 Unknown rtl819xSE (monitor mode enabled)