A default gateway allows a host to communicate with systems outside its local network. When a device needs to reach an IP address that is not in its own subnet, it sends the traffic to the default gateway, usually a router interface. The gateway then forwards the packet toward the destination based on routing information. A default gateway does not increase wireless signal strength, act primarily as a traffic buffer, or eliminate packet errors. Its essential role is forwarding traffic between networks when the local host does not have a more specific route. Without a default gateway, a device can usually communicate only with other devices on the same local subnet. Default gateways are fundamental in troubleshooting because incorrect gateway settings often cause users to reach local resources but fail to reach remote networks or the internet. Reference/topics: Network Fundamentals 2.3, default gateway; Network Fundamentals 2.5, routing.