Essential Linux Networking Commands Every Server Administrator Must Know

The Modern Linux Networking Toolkit

The traditional ifconfig and netstat commands are deprecated on modern systems. The ip and ss utilities from iproute2 are their replacements and provide far more information.

ip — Interface and Routing Management

ip addr show          # Show all interfaces and IPs
ip route show         # Show routing table
ip link show          # Show interface status
ip route add 10.0.0.0/8 via 192.168.1.1  # Add static route

ss — Socket Statistics

ss -tunlp             # Show all listening TCP/UDP sockets with PID
ss -s                 # Socket summary
ss -t state established  # Show established TCP connections

tcpdump — Packet Capture

tcpdump -i eth0 port 80          # Capture HTTP traffic
tcpdump -i eth0 host 8.8.8.8     # Traffic to/from specific IP
tcpdump -w capture.pcap           # Save to file for Wireshark analysis

nmap — Network Scanner

nmap -sV your-server-ip           # Service version scan
nmap -sC -sV -oA scan your-server # Full scan with scripts

FAQ

What replaced netstat on modern Linux?

The ss command replaces netstat. It is faster, more accurate, and provides more detail. Install with: apt install iproute2.