Inspect and configure network interfaces quickly from the shell. 25.03.2026 | reading time: 2 min When the network stops answering, where does he begin? `ifconfig` is the classic command-line tool to inspect and configure network interfaces on Unix-like systems, offering a fast way to read addresses, flags, and link status. Quick inspection: real output Inspect interfaces on a lab server by running the command and reading the output: ```bash ifconfig -a ``` Example output (trimmed for clarity): ``` eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.1.10 netmask 255.255.255.0 broadcast 192.168.1.255 ether 00:11:22:33:44:55 txqueuelen 1000 (Ethernet) lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 ``` Change addresses and state Do something useful: assign an IP or toggle an interface; for example he can run `ifconfig eth0 192.168.1.20 netmask 255.255.255.0` to set an address, and `ifconfig eth0 down` then `ifconfig eth0 up` to reset link state; use `ifconfig -a` to show all interfaces including those down. Limitations and when to switch A warning and a choice: `ifconfig` comes from the older net-tools suite and lacks many modern features; prefer the `ip` command from iproute2 for advanced routing, namespaces and scripting, but keep `ifconfig` for quick checks in rescue shells or on older distributions; also consider `ethtool` for link-level details and `nmcli` for NetworkManager-controlled systems. Next steps You now know how to read interface flags, set addresses and toggle links with `ifconfig`; push further by practicing `ip` and network troubleshooting, and consider formalizing skill with an exam such as CompTIA Linux+ or LPIC-1 using intensive exam preparation at bitsandbytes.academy. Join Bits & Bytes Academy First class LINUX exam preparation. network utilities troubleshooting
