I have aircrack-ng 1.1 on Ubuntu 14.04 and whenever I use the command "airmon-ng start wlan0", it always says "monitor mode enabled" instead of "monitor mode enabled on mon0". I checked ifconfig and iwconfig to see if it made another interface name. I have a Realtek RTL8187SE driver. How can I fix this problem?
You need to specify what channel you want your wireless card to operate on while in monitor mode.
Your command should read
airmon-ng start wlan0 wireless-channel 1 to 11
airmon-ng start wlan0 11 will put your wireless card in monitor mode on channel 11.
For more information check out the man page for airmon-ng