How IPv4 addressing, gateways, DNS, DHCP, NAT, and a small-office router work together on a local network.
TCP/IP configuration assigns an address to a host, defines the local network, supplies a route beyond it, and names remote services. A SOHO router commonly combines Wi-Fi, DHCP, NAT, and basic firewall functions.
| Setting or service | Role |
|---|---|
| IP address and subnet mask | Identify the host and its local network |
| Default gateway | Routes traffic to other networks |
| DNS | Resolves names to addresses |
| DHCP | Assigns configuration automatically |
| NAT | Lets private hosts share a public-facing address |
Private IPv4 ranges are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. A 169.254.0.0/16 link-local address commonly indicates that a client did not obtain an IPv4 lease through DHCP.
If a host can reach its gateway and an external IP address but cannot resolve names, focus on DNS. If it has a link-local address while other clients have normal addresses, focus on DHCP availability, cabling or Wi-Fi association, and the client configuration.