Quiz Entry - updated: 2026.07.14
What is a default gateway and what are its requirements?
A default gateway is a router (or Layer 3 switch) on the LAN that serves as the door to other networks; it must have an IP in the LAN's range and be able to forward traffic off the LAN.
Default Gateway (DGW): A router or Layer 3 switch that acts as the "door" to other networks.
Requirements for a default gateway:
| Requirement | Description |
|---|---|
| Same network | Must have an IP address in the same range as the LAN hosts |
| Accept LAN data | Can receive frames from devices on the local network |
| Route to other networks | Capable of forwarding traffic off the LAN |
How hosts learn the DGW:
- IPv4: Statically configured OR via DHCP
- IPv6: Via Router Solicitation (RS) message or manual configuration
Important:
If a device has no default gateway or a bad default gateway, its traffic will NOT be able to leave the LAN.
Context: The default gateway is a static route that acts as a "last resort" when no other route matches. All devices on a LAN need the DGW address to communicate with remote networks.
Go deeper:
Wikipedia — Default gateway — what the gateway does, with home and enterprise examples.