Ip command or nmcli? How to Choose

The short answer: use ip for quick, one-off checks and changes to network interfaces, addresses, and routes, and use nmcli when you need persistent, system-wide network configuration managed by NetworkManager. ip is a low-level tool that talks directly to the kernel; nmcli is a higher-level tool that talks to NetworkManager, which then applies settings and keeps them across reboots.

Background: Two Different Layers

Linux networking has two distinct layers. The kernel itself handles the actual network interfaces, IP addresses, and routing tables. Tools like ip (from the iproute2 package) manipulate these kernel objects directly. When you run ip addr add 192.168.1.10/24 dev eth0, the change happens immediately in the kernel, but it is gone after a reboot unless you also edit a config file or run a script.

NetworkManager is a daemon that sits on top of the kernel and provides a higher-level abstraction: connections. A connection is a named profile that stores all settings for a network (IP address, DNS, Wi-Fi SSID, etc.). nmcli is the command-line client for NetworkManager. When you use nmcli connection up "MyWiFi", NetworkManager reads that profile and applies the settings to the kernel, and it will do so automatically at boot if the connection is set to autoconnect.

How Each Command Works

ip is part of the iproute2 suite, which replaced the older ifconfig, route, and arp commands. Its syntax is object-based: ip [object] [command]. Common objects are link (interfaces), addr (IP addresses), and route (routing table). For example:

• ip link show – list all network interfaces
• ip addr show – show IP addresses
• ip route show – display the routing table
• ip link set eth0 up – bring an interface up
• ip addr add 192.168.1.10/24 dev eth0 – assign an IP address

nmcli has two main object groups: connection and device. The connection commands manage profiles, while device commands manage the actual hardware. Common examples:

• nmcli device status – show all devices and their state
• nmcli connection show – list saved connection profiles
• nmcli connection up "Wired" – activate a profile
• nmcli connection add type ethernet ifname eth0 ipv4.method manual ipv4.addresses 192.168.1.10/24 – create a persistent static IP profile

The key difference: ip changes the kernel state directly; nmcli changes NetworkManager’s configuration, which then updates the kernel state.

How to Choose: When to Use Which

There is no universal “best” – it depends on what you are doing. Use this as a rough guide:

• Quick troubleshooting: Use ip. If your network is down, NetworkManager might not even be running. ip addr show and ip route show give you raw kernel facts instantly.
• Persistent configuration: Use nmcli on a desktop or a server that uses NetworkManager. It saves profiles that survive reboots.
• Scripting a temporary change: Use ip if you want the change to last only until the next reboot or service restart.
• Wi-Fi connections: Use nmcli. Managing Wi-Fi with ip is painful because you need to handle wpa_supplicant separately. nmcli device wifi connect "SSID" password "..." is far simpler.
• Bonding, bridging, VLANs: Both can do it, but nmcli makes it easier to define persistent configurations. For a quick temporary bridge, ip link add is fine.

Common Problems and How to Avoid Them

One frequent mistake is using ip addr add without removing the old address first, which can leave you with two addresses on the same interface. Use ip addr flush dev eth0 before adding a new one if you want a clean slate.

Another problem: when you use ip to change an IP address, NetworkManager (if running) may not know about it and could override it later. If you see your changes disappearing, check if NetworkManager is managing that interface with nmcli device status. If it says “connected” or “unmanaged,” you may need to use nmcli instead.

A third issue: forgetting that ip changes are not persistent. A common question is “Why did my IP reset after reboot?” – because you used ip instead of nmcli or editing a config file.

Real-World Comparison: A Static IP Example

Suppose you want to set a static IP of 192.168.1.10/24 on eth0, with gateway 192.168.1.1, and have it survive a reboot.

With nmcli (on a NetworkManager system):

nmcli connection modify "Wired" ipv4.method manual ipv4.addresses 192.168.1.10/24 ipv4.gateway 192.168.1.1
nmcli connection up "Wired"

That’s it. The profile is saved and will be applied at boot.

With ip (temporary only):

ip addr add 192.168.1.10/24 dev eth0
ip route add default via 192.168.1.1

This works immediately, but after a reboot you lose it. To make it persistent with ip, you would need to edit /etc/network/interfaces (Debian/Ubuntu) or a netd script, which is more error-prone.

Alternatives and Related Tools

Beyond ip and nmcli, there are other tools you might encounter:

• nmtui – a text-based user interface for NetworkManager. Good if you prefer menus.
• ifconfig and route – legacy tools, still present on some systems but deprecated. ip replaces them.
• systemd-networkd – a different network manager used on some minimal systems. Its command-line tool is networkctl, and config files live in /etc/systemd/network.
• wicked – used on some SUSE systems, with its own wicked command.

If you are on a server without a desktop environment, check whether NetworkManager is even installed. Many minimal cloud images use systemd-networkd or plain ifupdown, in which case nmcli won’t exist and you should use ip plus config files.

Frequently Asked Questions

Is ip replacing ifconfig?

Yes, on modern Linux distributions ip is the standard tool. ifconfig is deprecated and often not even installed by default. The ip command is more powerful and consistent, but it has a steeper learning curve.

Can I use nmcli on a server without a GUI?

Yes, NetworkManager runs fine without a GUI. Many minimal server installs include it. You can check with systemctl status NetworkManager. If it’s not running, you can install it or use ip with config files.

Why does my ip change get overwritten?

If NetworkManager is managing that interface, it periodically applies its connection profiles, which can override manual ip changes. Use nmcli device status to see if the device is “connected” (managed). If so, use nmcli to make changes, or set the device as “unmanaged” with nmcli device set eth0 managed no.

Which command shows my current IP address?

Both. ip addr show shows all interfaces and addresses. nmcli device show gives more detailed info including DNS and routes. For a quick answer, ip -4 addr show filters to IPv4 only.

Is nmcli only for Wi-Fi?

No, nmcli manages all types of network connections: Ethernet, Wi-Fi, bridges, bonds, VLANs, and even VPNs. It’s just as useful for wired connections.

What if I don’t have nmcli installed?

Then you are likely using a system without NetworkManager – maybe a minimal container or an older distro. In that case, use ip for immediate changes and edit your distribution’s network config files (e.g., /etc/network/interfaces or /etc/sysconfig/network-scripts) for persistence.

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