What is a default gateway?

The default gateway is the router that a device sends packets to when the destination IP address is not on the local network. It is the "exit door" of the local network — the device uses its subnet mask to determine if the destination is local or not. If not local, it forwards the packet to the default gateway, which then routes it toward the destination. In a typical home network, the default gateway is the router's IP address (commonly 192.168.1.1 or 192.168.0.1). When no default gateway is configured, a device can only communicate with other devices on its local subnet. The default gateway must be on the same subnet as the device using it. Check your default gateway: route print (Windows), ip route (Linux), netstat -rn (macOS/Linux).