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Networking - A simpler alternative to 'NetworkManager'

If you're weary of constantly searching for the proper command to invoke some networking option in 'NetworkManager' (via nmcli or nmtui), or perhaps wondering, "What were "The Raspberries" thinking?!" when they threw over the relative simplicity of dhcpcd for the complexity of 'NetworkManager'... this recipe may offer some respite. At this point, you have two options: 1) read the following Background section, or 2) skip ahead to the implementation.

Background; some details and documentation

As of this writing, none of the following information is covered in the "Official" documentation for Raspberry Pi. Their coverage is limited to a few paragraphs on 'NetworkManager' - the "default" for 'bookworm'. Fortunately, Raspberry Pi is fundamentally a Debian distribution, and that gives us options. One of the simpler options for network configuration is available using ifupdown - a.k.a 'network interfaces' - as it uses the file /etc/network/interfaces. There is also a systemd service built for it under the inauspicious name networking.service, and it is ready-to-use!

As far as the Debian documentation goes - well, it's typical for Debian methinks... Most of the documentation applicable to this topic is in three places:

  1. Debian's NetworkConfiguration wiki
  2. Debian's WiFi wiki
  3. man interfaces on your system

By now you hopefully understand that ifupdown networking is simply network configuration that uses file located at /etc/network/interfaces. As you will see, this method of network configuration is quite simple, and works perfectly well for Raspberry Pi.

You may be wondering about the relationship between 'NetworkManager' and ifupdown. There's a statement on this page that explains it fairly succinctly:

NetworkManager will only handle interfaces not declared in /etc/network/interfaces

IOW, 'NetworkManager' defers control of any interface defined under /etc/network/interfaces to ifupdown. This seems reasonable, but my RPi systems only have (or use) a single interface... so what's the point of having 'NetworkManager' around at all? I'll address this question shortly.

You may also be harboring doubts about the future viability of ifupdown; or maybe heard rumors that it has been or may be deprecated. That seems highly unlikely to me, but you can get some insight into the discussion, and decide for yourself. Note that it is the first option listed in Debian's Network Configuration wiki.

One other thing before we get into the nitty-gritty required to implement our simplified network configuration: package dependencies. The Debian documentation states that there are some packages required for ifupdown networking. For WiFi, the Debian document lists these packages as required:

ifupdown, iproute2, wpasupplicant (aka wpa_supplicant; For WPA2 support), iw, and wireless-tools

You should check your system to be sure, but all of these packages were pre-installed (included) in the 64-bit Raspberry Pi OS Lite distro offered by "The Raspberries". Perhaps the easiest way to verify this is as follows:

$ sudo apt update
$ sudo apt install ifupdown iproute2 wpasupplicant iw wireless-tools
$
# you will *probably* receive a message fm 'apt' to the effect: "already latest version"
# if you installed 'trixie' from scratch, you'll probably need to install 'ifupdown'

A simpler network configuration:

Say hello to simplicity! Here's what's required:

  1. I'll use a WiFi configuration as an example; Ethernet is even simpler. We first create (or modify) the /etc/network/interfaces file as follows:

      $ sudo nano /etc/network/interfaces          # open the file in your favorite editor
  
  # add the following lines for a ***DHCP configuration***
  auto wlan0                       # alternatively: auto eth0
  iface wlan0 inet dhcp            # alternatively: iface eth0 inet dhcp
     wpa-ssid <MySSIDaccesspoint>
     wpa-psk <MySSIDpassword>
  # the loopback network interface
  auto lo
  iface lo inet loopback
  # ----------------------------------------------------------------------------
  # Alternatively, use the following for a ***static IP configuration***
  auto wlan0
  iface wlan0 inet static
     wpa-ssid <MySSIDaccesspoint>
     wpa-psk <MySSIDpassword>
     address 192.168.1.221                  # use values appropriate for your network
     netmask 255.255.255.0                  #              "
     gateway 192.168.1.1                    #              "
  # the loopback network interface
  auto lo
  iface lo inet loopback

  2. IMPORTANT: After making any changes to the /etc/network/interfaces file, you should check the status of the networking.service, and you must restart it:

    $ sudo systemctl status networking
$ sudo systemctl restart networking

    Failure to restart the networking.service may lock you out of an SSH connection.

  3. You should verify your network DNS settings also; this is stored in /etc/resolv.conf under ifupdown networking:

    $ sudo nano /etc/resolv.conf 

# For a ***DHCP configured host***:
domain yournetname.local
search yournetname.local
nameserver 192.168.1.1			# or whatever the IP addr of your Gateway/DNS server is

# For a ***static IP configured host***: 
domain yournetname.local
search yournetname.local
nameserver 192.168.1.1			# or whatever the IP addr of your Gateway/DNS server is
nameserver 8.8.8.8					# this is google's DNS, if you're using something else
nameserver 8.8.4.4					# then use that instead

  4. And that's it - that is all the configuration required! After editing and saving the /etc/network/interfaces and /etc/resolv.conf files, you may reboot. For reasons that are not yet clear to me, I had to perform a "cold boot" (i.e. pull power, then re-apply) on some systems instead of a reboot. Also, these changes may cause your DHCP server to issue a new IP address (as it did on my network)... consequently, if you're connecting over SSH you may need to change from a host name to the new IP address temporarily.

  5. Oh - a word to the wise before moving on. If you are setting up a static/fixed IP address, you should verify that it is actually working! One obvious thing to do is make an SSH connection to the fixed-IP host you've just provisioned. Another thing is to verify that this static IP host has DNS; i.e. from your SSH connection to your static-configured host try ping www.google.com or something similar. A working DNS is imperative for things such as system timekeeping and apt !

What's the point of having 'NetworkManager' around?

An earlier version of this recipe stated the following were optional steps. This was based on documentation found in Debian's wiki on Networking:

"By default it [NetworkManager] does not handle interfaces declared in /etc/network/interfaces"

However... I for one am not convinced that this bit of documentation matches the actual function of the software. My skepticism was aroused after I checked the contents of the /etc/network/interfaces file I had edited, and found that each and every line had been commented out!

That said, my advice here is to disable the NetworkManager.service once you have confirmed that your configuration in /etc/network/interfaces is functional and working. :

$ sudo systemctl disable NetworkManager.service

And while I have no reason to believe that the systemd-networkd.service is as nocuous as NetworkManager, I favor disabling it as well:

$ sudo systemctl disable systemd-networkd.service

Afterwards, you can check status of all 3 services; you should see this:

$ systemctl status NetworkManager.service
○ NetworkManager.service - Network Manager
     Loaded: loaded (/lib/systemd/system/NetworkManager.service; disabled; preset: enabled)
     Active: inactive (dead)
       Docs: man:NetworkManager(8)
$ systemctl status systemd-networkd.service
○ systemd-networkd.service - Network Configuration
     Loaded: loaded (/lib/systemd/system/systemd-networkd.service; disabled; preset: enabled)
     Active: inactive (dead)
TriggeredBy: ○ systemd-networkd.socket
       Docs: man:systemd-networkd.service(8)
             man:org.freedesktop.network1(5)
$ systemctl status networking.service
● networking.service - Raise network interfaces
     Loaded: loaded (/lib/systemd/system/networking.service; enabled; preset: enabled)
     Active: active (exited) since Fri 2025-02-28 22:02:27 UTC; 6min ago

Further explorations

For those of you who may be inclined to muck around with systemd a bit, I offer the following brief guide to systemd. I'm by no means an expert (heck, I don't even like systemd!); I used these commands in my exploration.

Useful systemd commands

# list enabled/disabled services on your system:
$ systemctl list-unit-files --state=enabled     # or --state=disabled 

# disable/enable services: 
$ sudo systemctl [enable | disable] <service_name> 

# mask/unmask a service: makes it “impossible” to load the service 
sudo systemctl [mask | unmask] <service_name>

# systemd report on time required for system boot
$ systemd-analyze time                          # or, 'systemd-analyze'
$ systemd-analyze blame
$ systemd-analyze critical-chain

# systemd general support & documentation
$ systemctl cat <service_name>
$ systemctl help <service_name>

Some useful systemd documentation

A good explanation of the difference between mask and disable

A helpful blog exploring use of systemd-analyze

RedHat Documentation: Optimizing systemd to shorten the boot time

The whole banana of systemd-analyze