# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 172.32.0.100 0.0.0.0 UG 0 0 0 usb0
172.32.0.0 0.0.0.0 255.255.0.0 U 0 0 0 usb0
# ping -I usb0 www.baidu.com
PING www.baidu.com (183.2.172.42): 56 data bytes
64 bytes from 183.2.172.42: seq=0 ttl=50 time=9.827 ms
64 bytes from 183.2.172.42: seq=1 ttl=50 time=9.258 ms
64 bytes from 183.2.172.42: seq=2 ttl=50 time=8.340 ms
64 bytes from 183.2.172.42: seq=3 ttl=50 time=8.994 ms
64 bytes from 183.2.172.42: seq=4 ttl=50 time=9.933 ms
64 bytes from 183.2.172.42: seq=5 ttl=50 time=8.321 ms
64 bytes from 183.2.172.42: seq=6 ttl=50 time=8.609 ms
64 bytes from 183.2.172.42: seq=7 ttl=50 time=9.013 ms
64 bytes from 183.2.172.42: seq=8 ttl=50 time=9.234 ms
64 bytes from 183.2.172.42: seq=9 ttl=50 time=9.284 ms
^C
--- www.baidu.com ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max = 8.321/9.081/9.933 ms