Master Curl, Wget, and NMCLI: Essential Linux Operations Commands

curl

curl

is a command‑line tool for transferring data over protocols such as HTTP, HTTPS, and FTP.

Basic usage

Fetch webpage content: curl http://example.com Download a file: curl -O http://example.com/file.zip Save to a specific filename: curl -o myfile.zip http://example.com/file.zip Test a port: curl -v ip:port Limit download speed:

curl --limit-rate 100K http://example.com

wget

wget

is a command‑line downloader supporting HTTP, HTTPS, and FTP.

Basic usage

Download a file: wget http://example.com/file.zip Download and rename: wget -O myfile.zip http://example.com/file.zip Background download: wget -b http://example.com/file.zip Show progress bar: wget --progress=bar http://example.com/file.zip Download specific file types (e.g., PDFs):

wget -r -A pdf http://example.com

Network bonding (bond)

Bonding combines multiple network interfaces to increase bandwidth or provide redundancy. Common modes:

mode=0 (Round‑robin): distributes outbound traffic evenly across all NICs.

mode=1 (Active‑backup): only one NIC is active; a backup takes over on failure.

mode=2 (XOR): uses MAC‑hash to assign traffic to NICs.

mode=3 (Broadcast): sends packets on all NICs.

mode=4 (802.3ad): LACP dynamic link aggregation.

mode=5 (TLB): adaptive transmit load balancing.

mode=6 (ALB): adaptive load balancing with ARP monitoring.

Configure bond with nmcli

1. Create bond interface
nmcli connection add type bond con-name bond0 ifname bond0 mode active-backup miimon 100

2. Add slave interfaces
nmcli connection add type bond-slave con-name bond0-slave1 ifname ens224 master bond0
nmcli connection add type bond-slave con-name bond0-slave2 ifname ens256 master bond0

3. Set static IP
nmcli connection modify bond0 ipv4.addresses 192.168.5.130/24 ipv4.gateway 192.168.5.1 ipv4.dns "8.8.8.8" ipv4.method manual

4. Enable DHCP
nmcli connection modify bond0 ipv4.method auto

5. Activate connections
nmcli connection up bond0
nmcli connection up bond0-slave1
nmcli connection up bond0-slave2

6. Verify status
cat /proc/net/bonding/bond0

Configure a regular NIC IP with nmcli

# List interfaces
nmcli device

# Create connection
nmcli connection add type ethernet ifname eth0 con-name eth0

# Set static IP
nmcli connection modify eth0 ipv4.addresses 192.168.5.110/24
nmcli connection modify eth0 ipv4.gateway 192.168.5.1
nmcli connection modify eth0 ipv4.dns 8.8.8.8
nmcli connection modify eth0 ipv4.method manual

# Enable DHCP
nmcli connection modify eth0 ipv4.method auto

# Show active connections
nmcli connection show --active