Frequently asked questions

It prints the TCP/IP configuration of every network adapter on a Windows computer: IPv4 and IPv6 addresses, subnet mask and default gateway, and with /all the MAC address, DHCP server, lease times and DNS servers. It can also release and renew DHCP leases and flush or display the DNS cache. It cannot change addresses or DNS servers; that is netsh or PowerShell.

It shows and sets network interface parameters on Unix-like systems: address, netmask, broadcast, MTU, hardware address and flags such as up, down and promiscuous. On Linux it is deprecated in favour of ip; on macOS and BSD it remains the standard tool.

No. Different platforms, different syntax, different abilities. ipconfig displays and manages DHCP/DNS on Windows; ifconfig displays and configures interfaces on Unix. Full comparison.

Modern Linux distributions no longer install the net-tools package that provides it. Use ip -br addr instead, or install net-tools with your package manager. Details for each distribution.

macOS has a command called ipconfig, but it is a different program that controls the DHCP client. ipconfig /all prints a usage message. Use ifconfig, ipconfig getifaddr en0 or networksetup -getinfo "Wi-Fi". macOS guide.

Local address: ipconfig (Windows), ip -br addr (Linux), ipconfig getifaddr en0 (macOS). Public address: visit the checker or run curl ipconfig.co.uk/ip.

DHCP failed and the system self-assigned a link-local address. You will not have internet access. Check the link, then release and renew; if that fails, the DHCP server (usually your router) is the problem. Step by step.

Release gives the current DHCP lease back and leaves the adapter without an address. Renew asks the DHCP server for a lease. Running release then renew forces a fresh negotiation; renew alone usually just extends the existing lease with the same address.

Usually not. DHCP servers re-issue the address you had. To get a different local address, release, then delete the lease or reservation on the router, then renew. Your public address is assigned by your ISP to the router and is unaffected by anything you do on the computer; some ISPs change it when the router is powered off for a while.

Windows: ipconfig /flushdns. macOS: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder. Linux with systemd-resolved: sudo resolvectl flush-caches. Browsers have their own caches. All platforms.

One link-local (fe80::) always; one stable global address from SLAAC; one or more temporary privacy addresses that rotate daily; possibly a DHCPv6 address on corporate networks; and old temporary addresses marked deprecated. All normal. IPv6 address types.

The zone ID: which interface the link-local address belongs to, since every interface has an fe80:: address. Windows uses the interface index; Linux and macOS use the interface name (%eth0, %en0).

ip is the modern Linux replacement, using the kernel's netlink interface. It shows all addresses on an interface, handles routes, neighbours, namespaces, VLANs, bridges and tunnels, and has JSON output. ifconfig on Linux is frozen 1990s software that hides secondary addresses. Translation table.

No. Both change the live kernel state only. Persistent settings live in NetworkManager profiles (nmcli), systemd-networkd files, Netplan YAML, or /etc/network/interfaces. On macOS, networksetup makes persistent changes. Linux configuration.

Windows: netsh interface ipv4 set address "Ethernet" static 192.168.1.50 255.255.255.0 192.168.1.1. Linux (persistent): nmcli con mod "Wired connection 1" ipv4.method manual ipv4.addresses 192.168.1.50/24 ipv4.gateway 192.168.1.1. macOS: sudo networksetup -setmanual "Wi-Fi" 192.168.1.50 255.255.255.0 192.168.1.1. Cheat sheet.

The router that forwards traffic off your local network. Blank means no route to the internet: DHCP did not supply one, a static configuration omitted it, or a VPN removed it. Fix.

The adapter has no link: cable unplugged, Wi-Fi not associated, or adapter disabled. Address information is not shown because none exists. Fix.

Virtualisation and VPN software add virtual adapters: vEthernet (Hyper-V, WSL, Docker), VirtualBox Host-Only, VMware Network Adapter VMnet1/8, TAP-Windows, WireGuard, Tailscale, Bluetooth Network Connection, and IPv6 tunnel adapters (Teredo, ISATAP). They are normal. Disable any belonging to software you have removed.

ipconfig /all (Physical Address) or getmac on Windows; ip link on Linux; ifconfig en0 | grep ether on macOS. Phones show it under Wi-Fi details, though they randomise it per network by default.

No. NAT hides your local IPv4 address; the MAC never leaves the local segment. A website sees your public address (or your VPN's). Historically WebRTC could leak local addresses in browsers, but modern browsers use mDNS obfuscation to prevent it.

The labels are localised; on German Windows you see IPv4-Adresse. Scripts that grep for English labels break. Use PowerShell (Get-NetIPConfiguration), whose property names are the same everywhere.

Release and renew change the adapter state through the DHCP Client service, which requires elevation. Flushing the DNS cache is treated as a low-risk per-machine operation and is allowed for any user on standard Windows, though Group Policy can restrict it.

Not as such. ip -br addr gives the equivalent overview, ip route the gateway, resolvectl status the DNS servers, and nmcli a combined view. Termux and BusyBox environments also have ifconfig.

It shipped only with Windows 95, 98 and Me. Every later Windows uses ipconfig from the command line, or Settings › Network & internet for a graphical view.

Nothing. ip accepts any unambiguous prefix of an object or command name. ip a, ip ad, ip addr and ip address are identical, as are ip r and ip route.