Configuring wired network connection with WiFi still enabled
In systems with two interfaces (such as this Android device with wlan0 and eth0), routing is not automatically setup to use two gateways. This is why 'traceroute' shows that the traffic that you'd like to go out on `eth0' is actually going out on 'wlan0'.

Another way to confirm this is:

# ip route get 172.16.100.2
172.16.100.2 via 10.1.0.1 dev wlan0 &lt;snip&gt;


The solution is to configure multiple default routes by adding a new routing table for traffic on 'eth0' and then adding appropriate rules to the routing rule set. See this article for an example. (Even though the article describes a Linux system, the two commands you need to use, namely 'ip route' and 'ip rule', are available in Android.)