Network Commands

Network connectivity testing and diagnostics

# Ping host
ping google.com

# Ping with specific count
ping -c 4 google.com

# Ping with interval
ping -i 2 google.com

# Ping with timeout
ping -W 5 google.com

# Ping with packet size
ping -s 1000 google.com

# Ping IPv6 address
ping6 ipv6.google.com

# Ping with timestamp
ping -D google.com

Network connection and routing information

# Show all connections
netstat -a

# Show listening ports
netstat -l

# Show TCP connections
netstat -t

# Show UDP connections
netstat -u

# Show with process information
netstat -p

# Show with numerical addresses
netstat -n

# Show routing table
netstat -r

# Show interface statistics
netstat -i

Socket statistics and connection monitoring

# Show all sockets
ss -a

# Show listening sockets
ss -l

# Show TCP sockets
ss -t

# Show UDP sockets
ss -u

# Show with process information
ss -p

# Show with numerical addresses
ss -n

# Show socket statistics
ss -s

# Show sockets by state
ss -t state established

File downloading and web content retrieval

# Download file with curl
curl -O https://example.com/file.txt

# Download with wget
wget https://example.com/file.txt

# Download with progress bar
curl -# -O https://example.com/file.txt

# Download with resume capability
wget -c https://example.com/file.txt

# Download with custom user agent
curl -A "Custom Agent" https://example.com/

# Download with authentication
curl -u username:password https://example.com/

# Download with headers
curl -H "Accept: application/json" https://api.example.com/

# Download with timeout
curl --max-time 30 https://example.com/

Secure remote access and file transfer

# Connect to remote host
ssh user@hostname

# Connect with specific port
ssh -p 2222 user@hostname

# Connect with key file
ssh -i ~/.ssh/id_rsa user@hostname

# Execute command remotely
ssh user@hostname "ls -la"

# Copy files with scp
scp file.txt user@hostname:/path/

# Copy directory with scp
scp -r directory/ user@hostname:/path/

# Copy from remote to local
scp user@hostname:/path/file.txt ./

# Setup SSH tunnel
ssh -L 8080:localhost:80 user@hostname