How traffic leaves your network.
WHAT A DEFAULT GATEWAY IS
The device traffic is sent to when the destination is not on the local network.
Usually your router.
WHAT HAPPENS WITHOUT ONE
Local communication works; nothing beyond the network does.
WHAT THAT LOOKS LIKE
You can reach the printer but not the internet.
That symptom points directly at the gateway.
WHAT ROUTING MEANS
Deciding where to send traffic next.
Each router along a path makes that decision independently.
WHAT A ROUTING PROBLEM LOOKS LIKE
Some destinations reachable and others not A path that works from one network and not another
HOW TO OBSERVE THE PATH
A trace tool shows each hop between you and a destination.
WHAT IT TELLS YOU
Where the path stops, or where delay appears.
WHAT TO BE CAREFUL INTERPRETING
Some devices along a path do not respond to trace requests.
A gap does not necessarily mean a fault.
WHAT TO CHECK FIRST
That your device has the correct gateway.
