Watch the kernel pick a route. L3

Your host has a routing table. Every packet checks it. Type a destination and watch the decision happen, row by row.

Destination
Tap a destination. The host will create a packet, walk the routing table, and forward it through the winning interface.
Idle
Waiting for a destination.
Host
Host
mission-host
Gateway
192.168.1.1
eth0
10.0.5.2/24
Wired LAN
wlan0
192.168.1.10/24
WiFi
lo
127.0.0.1/8
Loopback
Routing Table (ip route show)
Destination Gateway Dev Proto Scope Src Metric Verdict
What just happened
host:~$