Linux Network Information
This document provides commands to retrieve your public IP address and detailed network information on Linux systems.
One-Liner for Quick Public IP​
If you just need a quick one-liner to get your public IP address:
curl -s https://api.ipify.org
# Alternative with ipinfo.io (returns JSON with additional data)
curl -s https://ipinfo.io/json | jq
Getting Your Public IP Address​
There are several ways to retrieve your public IP address using command-line tools:
Method 1: Using an External Service​
# Using ipify API
curl -s https://api.ipify.org
# Alternative with icanhazip
curl -s https://icanhazip.com
# Alternative with ipinfo.io (returns JSON with additional data)
curl -s https://ipinfo.io/json | jq
Method 2: Using DNS Services​
# Using OpenDNS
dig +short myip.opendns.com @resolver1.opendns.com
# Using Google DNS
dig TXT +short o-o.myaddr.l.google.com @ns1.google.com | tr -d \"
Getting Detailed Network Information​
Basic Network Interface Information​
# List all network interfaces
ip link show
# Show only active interfaces
ip link show up
# Display interface details with IP addresses
ip addr show
IP Configuration (Similar to ifconfig)​
# Get all IP configurations (ifconfig alternative)
ip addr
# Get only IPv4 addresses
ip -4 addr
# Traditional ifconfig (if installed)
ifconfig
Routing Information​
# Show routing table
ip route
# Traditional route command (if installed)
route -n
Network Statistics​
# Get network interface statistics
ip -s link
# Get TCP connection statistics
ss -s
# Get active connections
ss -tuln
# Traditional netstat (if installed)
netstat -tuln
DNS Client Information​
# View DNS resolver configuration
cat /etc/resolv.conf
# Test DNS resolution
dig google.com
# Trace DNS resolution
dig +trace google.com
Wi-Fi Networks (If Applicable)​
# Show available Wi-Fi networks
sudo iwlist scan | grep ESSID
# Show current Wi-Fi connection
iwconfig
# More detailed Wi-Fi information
nmcli dev wifi list
Comprehensive Network Report​
The following script creates a comprehensive network information report:
#!/bin/bash
# Create a network report
echo -e "\n\e[1;32mComprehensive Network Report\e[0m"
echo -e "\n\e[1;32mComputer Name:\e[0m"
hostname
echo -e "\n\e[1;32mPublic IP Address:\e[0m"
curl -s https://api.ipify.org || echo "Unable to retrieve (check internet connection)"
echo -e "\n\e[1;32mNetwork Interfaces:\e[0m"
ip link show up
echo -e "\n\e[1;32mIP Configuration:\e[0m"
ip -4 addr
echo -e "\n\e[1;32mDefault Gateway:\e[0m"
ip route | grep default
echo -e "\n\e[1;32mDNS Servers:\e[0m"
cat /etc/resolv.conf | grep nameserver
echo -e "\n\e[1;32mActive Connections:\e[0m"
ss -tuln
echo -e "\n\e[1;32mNetwork Interface Statistics:\e[0m"
ip -s link
echo -e "\n\e[1;32mInternet Connectivity:\e[0m"
ping -c 1 google.com > /dev/null && echo "Connected" || echo "Not connected"
Save this script as network_report.sh, make it executable with chmod +x network_report.sh, and run it whenever you need detailed network information.
Network Performance Testing​
# Install and use speedtest-cli
sudo apt install speedtest-cli # Debian/Ubuntu
sudo dnf install speedtest-cli # Fedora
speedtest-cli
# Test latency to a specific host
ping -c 5 google.com
# Test MTU
ping -c 5 -M do -s 1472 google.com
Save these commands to a bash script (.sh file) for easy access whenever you need network information.