DNS Explained Simply | Generated by AI
What Does DNS Mean?
DNS stands for Domain Name System. It’s essentially the “phonebook” of the internet (and local networks). It translates human-readable domain names (like www.example.com or google.com) into machine-readable IP addresses (like 192.0.2.1 or 8.8.8.8). Without DNS, you’d have to remember and type raw IP addresses to visit websites, which would be impractical.
DNS works hierarchically: Your device queries a DNS server (a specialized server that handles these lookups), which either knows the answer or forwards the query up the chain to authoritative servers until it resolves the name to an IP.
Configuring DNS on macOS or Windows
When you configure network settings on macOS (in System Settings > Network) or Windows (in Settings > Network & Internet > Ethernet/Wi-Fi > Properties), the DNS section lets you specify DNS servers manually or use defaults provided by your network. Common defaults include:
- Your ISP’s DNS servers.
- Public ones like Google’s
8.8.8.8and8.8.4.4, or Cloudflare’s1.1.1.1.
If you leave it on “Automatic” (often via DHCP, as you mentioned), your router or network provides these DNS servers for you.
The other details you listed:
- 192.168.1.1: This is typically your router’s local IP address (the “default gateway”). It’s the door to the outside internet from your home network.
- IPv4 Use DHCP: DHCP (Dynamic Host Configuration Protocol) is a service that automatically assigns IP addresses and other network info to devices on your network. “Use DHCP” means your computer doesn’t pick a static IP; instead, it asks the DHCP server (usually your router) for one dynamically.
How Your Computer Connects to the Network and Handles IP/Host Queries
Let’s break down the process step by step when your computer “visits the network” (i.e., connects to Wi-Fi or Ethernet):
- Initial Connection and DHCP Handshake:
- When you connect, your computer broadcasts a DHCP “discover” request: “Hey, anyone got an available IP address for me?”
- Your router (acting as the DHCP server) responds with an “offer”: “Sure, here’s an IP for you (e.g., 192.168.1.100), plus your subnet mask (e.g., 255.255.255.0), default gateway (192.168.1.1), and DNS server IPs (e.g., 8.8.8.8).”
- Your computer accepts (“request”) and confirms (“acknowledge”). Now it has everything to communicate on the local network.
- This doesn’t involve DNS yet—it’s just for your device’s own IP and basic routing. Your “host” (hostname, like your computer’s name) might be set locally on your device or registered with the router for local name resolution, but that’s separate.
- Resolving Hosts (Where DNS Comes In):
- Once connected, if you try to visit
www.google.com, your computer doesn’t know the IP yet. It sends a DNS query to the DNS server(s) provided by DHCP (could be the router’s IP or an external one). - Does it go to the router? Often yes, indirectly:
- If your router is configured as a DNS proxy/forwarder (common in home routers like from TP-Link, Netgear, or Apple Airport), your computer queries the router first (e.g., via 192.168.1.1 as the DNS server).
- The router checks its local cache (for speed). If it has the answer (from a prior query), it responds directly. If not, it forwards the query to an upstream DNS server (like your ISP’s or a public one you set).
- The upstream DNS server resolves it (e.g.,
www.google.com→142.250.190.14) and sends the IP back through the chain to your computer. - Your computer then uses that IP to connect to the site.
- Once connected, if you try to visit
- How the Router Handles These Queries:
- DHCP Queries: The router maintains a pool of available IPs (e.g., 192.168.1.50 to 192.168.1.150). When you request one, it leases it to you for a set time (e.g., 24 hours), tracks it in its table, and renews if needed. It also handles your hostname if you set one (e.g., for local access like
ping mylaptop.local). - DNS Queries: The router doesn’t “own” DNS records—it’s a middleman. It:
- Caches responses to avoid repeated upstream queries (improves speed and reduces bandwidth).
- Forwards unresolved queries to configured upstream servers.
- May apply parental controls, ad-blocking (via custom DNS like Pi-hole), or logging.
- If the query is for a local device (e.g., another computer on your network), it might resolve it via its local hosts file or mDNS (multicast DNS, used by Bonjour on macOS/Apple devices).
- Errors? If DNS fails (e.g., wrong server IP), you can’t resolve names—sites won’t load, but pinging IPs directly might work.
- DHCP Queries: The router maintains a pool of available IPs (e.g., 192.168.1.50 to 192.168.1.150). When you request one, it leases it to you for a set time (e.g., 24 hours), tracks it in its table, and renews if needed. It also handles your hostname if you set one (e.g., for local access like
In short: DHCP gets your computer its “address and directions” from the router. DNS then uses those directions to ask “Where’s this website?”—often routing through the router to external resolvers.
If you’re troubleshooting a specific setup, share more details like your router model or exact error!