i have 3 network cards , 1 Lan (wired) , 1 wireless network card & 1 is wireless usb
how do i ping from specific network card ?
& how do i use specific network card for specific application
example
i want to ping google from wlan0
example for specific application
i want to use firefox or transmission from wan1
UPDATED
Lan ip 192.168.0.2 > Working Properly

Wlan1 ip 192.168.0.3

pin -I wlan1 google.com
UPDATE
Try pasting the output of route -n and/or ip route. Seems to me that the wlan1 interface hasn't a valid gateway configured. –@MrShunz
one@onezero:~$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0
172.16.221.0 0.0.0.0 255.255.255.0 U 0 0 0 vmnet8
192.168.0.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 2 0 0 wlan1
192.168.48.0 0.0.0.0 255.255.255.0 U 0 0 0 vmnet1
one@onezero:~$ ip route
default via 192.168.0.1 dev eth0 proto static
169.254.0.0/16 dev eth0 scope link metric 1000
172.16.221.0/24 dev vmnet8 proto kernel scope link src 172.16.221.1
192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.2 metric 1
192.168.0.0/24 dev wlan1 proto kernel scope link src 192.168.0.3 metric 2
192.168.48.0/24 dev vmnet1 proto kernel scope link src 192.168.48.1