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    DNS vs DHCP

    Both services run quietly on every home network and both break the internet when they fail — but they solve completely different problems.

    Short answer

    DHCP assigns your device an IP address, gateway and DNS server. DNS then translates hostnames like example.com into IP addresses.

    DNS vs DHCP at a glance

    DNS vs DHCP comparison table
    AttributeDNSDHCP
    PurposeName → IP resolutionAddress assignment
    Ports53 (UDP/TCP), 853 DoT, 443 DoH67/68 UDP
    Runs whenEvery new connectionAt join and lease renewal
    Configurable per deviceYesYes, via static IP
    Failure symptom"Site can't be reached", IPs still workNo IP address, no connectivity at all
    CachingHeavy, TTL-basedLease-based

    Pros and cons

    DNS

    • Choice of resolver improves speed and filtering
    • Encryptable with DoH/DoT
    • Cache poisoning risk
    • Slow resolvers delay every page

    DHCP

    • Zero-configuration networking
    • Central control of options
    • Single point of failure
    • Rogue servers can hijack a LAN

    Which should you choose?

    Recommended choice per scenario
    If this is youPick
    Pages fail but direct IPs workCheck DNS
    Device shows 169.254.x.xCheck DHCP
    Blocking ads network-wideDNS filtering
    Reserving printer addressesDHCP reservation

    Frequently Asked Questions

    Get answers to common questions about internet speed testing.