Daily Linux Command: Ip

<span>ip</span> command is a powerful tool for network interface configuration and management in Linux systems, part of the <span>iproute2</span> software package. It replaces the outdated <span>ifconfig</span>, <span>route</span>, and <span>arp</span> commands, offering more powerful and flexible functionality.

📌 Basic Syntax

ip [options] object [command] [parameters]

Common objects include:

• <span>link</span>: network interfaces (e.g., eth0, wlan0)
• <span>addr</span> or <span>address</span>: IP address
• <span>route</span>: routing table
• <span>neigh</span>: ARP/NDP cache (neighbor table)
• <span>rule</span>: policy routing rules

🔧 Common <span>ip</span> Command Examples

1. View Network Interface Information (Equivalent to the old ifconfig)

ip link show

Description: Displays the status (UP/DOWN), MAC address, etc., of all network interfaces.

👉 To view a specific interface:

ip link show dev eth0

2. Enable or Disable Network Interfaces

# Enable eth0
ip link set eth0 up

# Disable eth0
ip link set eth0 down

3. View or Set IP Addresses

View IP Address:

ip addr show

Or shorthand:

ip a

👉 View a specific interface:

ip addr show dev eth0

Add IP Address:

ip addr add 192.168.1.100/24 dev eth0

Delete IP Address:

ip addr del 192.168.1.100/24 dev eth0

4. Manage Routing

View Routing Table:

ip route show

Or shorthand:

ip r

Add Default Gateway:

ip route add default via 192.168.1.1 dev eth0

Add Static Route:

ip route add 10.0.0.0/8 via 192.168.1.1 dev eth0

Delete Route:

ip route del 10.0.0.0/8

5. View Neighbor Table (Similar to arp -a)

ip neigh show

Clear a specific neighbor entry:

ip neigh del 192.168.1.1 lladdr aa:bb:cc:dd:ee:ff dev eth0

Force refresh:

ip neigh flush dev eth0

6. Display Network Statistics

ip -s link show dev eth0

This will display the number of packets sent and received, errors, and other statistics.

7. Use Color Highlighting for Output (for better readability)

ip -color a

8. Monitor Network Events (Dynamically Observe Changes)

ip monitor all

This can monitor changes in interfaces, addresses, and routes in real-time.

Only monitor route changes:

ip monitor route

✅ Comparison with Old Commands (Migration Reference)

Old Command	New ip Command
<span>ifconfig</span>	<span>ip addr</span> / <span>ip link</span>
<span>ifconfig eth0 up</span>	<span>ip link set eth0 up</span>
<span>route -n</span>	<span>ip route show</span>
<span>route add ...</span>	<span>ip route add ...</span>
<span>arp -a</span>	<span>ip neigh show</span>

⚠️ Notes

• Executing the <span>ip</span> command to modify network configurations is usually temporary and will not persist after a reboot. For persistence, modify the network configuration files (e.g., <span>/etc/network/interfaces</span> or use NetworkManager, systemd-networkd).
• Root privileges are required to modify interfaces, routes, etc. (use <span>sudo</span>):

  sudo ip link set wlan0 up

💡 Tips

• Using Tab completion can help you quickly input <span>ip</span> subcommands.
• <span>ip help</span> or <span>ip -h</span> can be used to view help.
• Combine usage: <span>ip a && ip r</span> to view addresses and routes simultaneously.