We have recently spoken about IP routing, but there is something else that needs our attention, and it is all about the types of routes found in a routers routing table. It might sound confusing but ...

Routers (and Layer 3 switches) perform table lookups determining the next hop (next router or Layer 3 switch) along the route, which in turn determines the output port over which to forward the packet ...

Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 10.0.0.1 0.0.0.0 UG 0 0 0 eth0 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 ...

You need to understanding routing tables if you're going to do any kind of network troubleshooting. Let's take a look at what Linux commands can tell you about how your system is making connections.