Default gateway
A default gateway is the router or forwarding path to which a host sends traffic destined for networks absent from its routing table.
Acing the CCNA Exam: Volume 1 Fundamentals and Protocols
A default gateway is the router or forwarding path used to send traffic toward destinations outside a device's known networks.
- How it is used
- Explains how end hosts reach destinations outside their local networks.
- How deep it goes
- Traces subnet comparison, ARP resolution, frame addressing, router lookup, and forwarding, while deferring detailed routing-table construction.
- Examples
- Uses PC1, PC2, PC3, R1, ipconfig output, ARP exchange, and Cisco routing-table output.
- What you can do after
- Diagnose gateway addressing and ARP behavior using ipconfig and packet-flow reasoning.
Read how Acing the CCNA Exam: Volume 1 Fundamentals and Protocols explains default gateway →
Acing the CCNA Exam: Volume 2 Advanced Networking and Security
A default gateway is the router to which a host sends packets destined for networks absent from its routing table.
- How it is used
- Enables hosts to communicate with devices outside their local LAN through a router.
- How deep it goes
- Defines the gateway’s role, relates it to netmasks, and demonstrates route verification on macOS without detailing router internals.
- Examples
- Uses macOS ifconfig output and netstat -rn output showing 192.168.1.1 as the default gateway.
- What you can do after
- Diagnose a macOS host’s configured default gateway by inspecting its routing table.
Read how Acing the CCNA Exam: Volume 2 Advanced Networking and Security explains default gateway →
Related concepts
- routerkind of · A router is a network device that forwards packets between networks based on destination addresses and routing information.
- dhcpproduced by · The Dynamic Host Configuration Protocol (DHCP) is a network protocol that automatically assigns devices IP addresses and related configuration information.
- first hop redundancy protocolproduced by · A first-hop redundancy protocol provides hosts with resilient default-gateway service through a virtual gateway backed by multiple routers.
- arpused by · The Address Resolution Protocol is a local-network protocol that maps an IPv4 address to the corresponding link-layer address, typically a MAC address.
- virtual ip addressconfigured by · A virtual IP address is a logical network address representing a service or routing endpoint independently of a particular physical host or interface.
- network switchused by · A network switch is a device that connects devices within a local network and selectively forwards data-link-layer frames to their intended destinations.
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