ipconfig

ipconfig is a Windows command-line utility that displays and manages TCP/IP network configuration on local network adapters.

What ipconfig Does and When to Use It

ipconfig ships with every version of Windows since Windows NT and provides direct access to the TCP/IP configuration of all network adapters on a computer. The utility reads the current IP address, subnet mask, default gateway, DNS server addresses, and DHCP lease status for each adapter. On older Windows 95/98/ME systems, this utility was named winipcfgand included a graphical interface.

ipconfig serves two roles: displaying network configuration and managing DHCP leases and DNS resolver cache. The display commands ( ipconfig and ipconfig /all) read the current state without changing anything. The management commands ( /release, /renew, /flushdns, /registerdns) modify the active network configuration by communicating with DHCP servers or the local DNS resolver.

Use ipconfig when troubleshooting network connectivity issues on Windows. The utility helps diagnose problems such as missing IP addresses, expired DHCP leases, stale DNS cache entries, and missing default gateway assignments. ipconfig does not configure static IP addresses or modify adapter settings permanently -- use the Windows Network Adapter Properties dialog or netsh for persistent changes. On Linux and macOS, the equivalent utility is ifconfig or ip addr.

Core Concepts of ipconfig

DHCP and ipconfig

Dynamic Host Configuration Protocol (DHCP) assigns IP addresses to network adapters automatically. ipconfig interacts with the DHCP server through the /release and /renew commands. The /release command tells the DHCP server to revoke the current IP address lease. The /renew command requests a new lease from the DHCP server.

ipconfig DHCP commands work only on adapters configured for automatic IP assignment. Adapters with manually assigned static IP addresses ignore /release and /renew commands. The DHCP server typically runs on the local router, while the network adapter acts as the DHCP client.

IP Address, Subnet Mask, and Default Gateway in ipconfig

ipconfig displays three core TCP/IP values for each network adapter: the IPv4 address, the subnet mask, and the default gateway. The IPv4 address identifies the computer on the local network. The subnet mask defines the boundary of the local network segment. The default gateway is the router address that forwards traffic to external networks.

DNS Resolver Cache and ipconfig

ipconfig manages the local DNS resolver cache through the /displaydns and /flushdns commands. The DNS resolver cache stores recent domain-to-IP-address mappings to speed up repeated lookups. The /flushdns command clears all cached DNS entries and forces Windows to fetch fresh records from the configured DNS server.

Common Tasks with ipconfig

How to View Network Configuration with ipconfig

Run ipconfig in Windows Command Prompt to display the IP address, subnet mask, and default gateway for each active network adapter:

ipconfig

Run ipconfig /all to display detailed TCP/IP configuration including the MAC address (Physical Address), DHCP status, DNS servers, and lease timestamps:

ipconfig /all

How to Release and Renew an IP Address with ipconfig

Release the current DHCP-assigned IP address and request a new one from the DHCP server:

ipconfig /release
ipconfig /renew

ipconfig sends a DHCPRELEASE message to the router, then sends a DHCPDISCOVER message to obtain a new IP address lease. This two-step process resolves most DHCP-related connectivity issues.

How to Flush the DNS Cache with ipconfig

Clear the local DNS resolver cache to force Windows to fetch updated DNS records:

ipconfig /flushdns

ipconfig confirms the flush with a "Successfully flushed the DNS Resolver Cache" message. Use this command after DNS record changes to ensure the computer resolves the correct IP address for a domain.

How to Run ipconfig

ipconfig runs from the Windows Command Prompt application:

1. Type cmd in the Windows search bar to open the Command Prompt app:

   

2. Type ipconfig and press Enter:

   

ipconfig Command Reference

ipconfig Troubleshooting

Related Tools and Guides

netsh is the Windows command-line tool for advanced network configuration. Use netsh to set static IP addresses, configure firewall rules, and reset the TCP/IP stack. See netsh interface ip set addressfor static IP assignment.

ifconfig is the equivalent utility on Linux and macOS systems. The ifconfig command displays and configures network adapter settings on Unix-based operating systems. On modern Linux distributions, the ip addr command from the iproute2 package replaces ifconfig.

nslookup is a Windows DNS diagnostic tool that queries DNS servers directly. Use nslookup to test DNS resolution independently from the local DNS resolver cache that ipconfig manages.