Raspberry Pi Network Manager

Setting up a Static IP Address (an IP address that does not change)

The Raspberry Pi OS Bookworm version now uses Network Manager (nm) by default for network configuration, instead of dhcpcd which was used previously.

Network Manager manages the network based on "connections".

On a fresh system, it creates a default wired connection called "Wired Connection 1" and a default wireless connection based on the SSID provided during setup.

Check Active Network Services

To confirm which networking service your system is using, you can check for active network-related services:

systemctl list-units --type=service | grep -i network

Output

networking.service                    loaded active exited 
NetworkManager-dispatcher.service     loaded active running Network Manager 
NetworkManager-wait-online.service    loaded active exited  Network Manager 
NetworkManager.service                loaded active running Network Manager

The output shows the Raspberry Pi is using NetworkManager as its primary tool for managing network connections.

This is indicated by the presence of NetworkManager.service marked as loaded active running. Additionally, you have networking.service which typically handles traditional networking scripts but seems to be managing less in this setup given that NetworkManager is also active.

Key Points about Network Manager

1. Connection information is stored in /etc/NetworkManager/system-connections/*.nmconnection files which must have 600 file permissions. Editing these requires restarting the connection or rebooting.

2. The nmcli command line tool allows managing connections - viewing attributes, bringing connections up/down, modifying attributes, renaming, etc. Tab completion is supported.

3. nmtui provides a text user interface as an easier alternative to nmcli for complex setups without needing to remember all the nmcli details.

4. Connection files can be copied between systems for reuse. The UUIDs don't seem to cause issues.

5. Enabling a captive portal connection automatically enables IP forwarding, which may need to be manually disabled using sysctl if undesired.

6. For headless setup, it's recommended to switch from dhcpcd to NetworkManager on a running Bullseye system first before doing a dist-upgrade to Bookworm. Directly switching using raspi-config in a headless setup can lead to loss of network access.

7. Overall, Network Manager is seen as more user-friendly and a standard across Linux distros compared to the previous dhcpcd setup on Raspberry Pi OS. But it has a learning curve for those used to the old way.

If Network Manager is not installed

The last task we need to complete before we enable Network Manager on our Raspberry Pi is to install the actual software.

To install the “network-manager” package to your device, run the command below in the terminal.

sudo apt install network-manager

Set Static IP via NetworkManager

Here’s how you can proceed with setting a static IP address through NetworkManager:

Requirements

• Raspberry Pi running Raspberry Pi OS (Debian-based Linux)

• Access to a terminal or SSH session on the Raspberry Pi

• NetworkManager Installed

Checking Network Manager status: To verify if Network Manager is running, use the following command:

nmcli -t -f RUNNING general

We need to collect four important pieces of information first

[your-static-ip]

[router-ip]

[dns-ip]

[dns-search-domain]

To find the placeholder details for configuring a static IP address using Network Manager, you need to gather the following information:

Static IP Address ([your-static-ip])

• Determine the static IP address you want to assign to your device.

• It should be an available IP address within your network's range.

• Example: 192.168.1.100

Check the current IP address

hostname -I

Note down the IP address displayed.

For example: 192.168.68.64

Subnet Mask

• The subnet mask is usually denoted by /24 for a typical home network, which corresponds to 255.255.255.0.

• Adjust the subnet mask according to your network's configuration.

ip addr show wlan0

The output:

wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 2c:cf:67:2c:91:1a brd ff:ff:ff:ff:ff:ff
    inet 192.168.68.67/22 brd 192.168.71.255 scope global dynamic noprefixroute wlan0
       valid_lft 5851sec preferred_lft 5851sec
    inet6 fe80::62a8:8dd9:cb43:c3b1/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

From the output inet 192.168.68.64/22, the /22 is the CIDR (Classless Inter-Domain Routing) notation that represents the subnet mask.

This notation indicates that the first 22 bits of the IP address are used to identify the network part of the address, with the remaining bits (out of 32 in total for IPv4) available for host addresses.

Identifying all network interfaces

First, get a detailed list of all interfaces with nmcli device status:

nmcli device status

The output

DEVICE         TYPE      STATE                   CONNECTION    
wlan0          wifi      connected               preconfigured 
lo             loopback  connected (externally)  lo            
docker0        bridge    connected (externally)  docker0       
p2p-dev-wlan0  wifi-p2p  disconnected            --            
eth0           ethernet  unavailable             --    

What does the output mean?

wlan0

• Type: wifi (Wireless LAN interface)

• State: connected

• Connection: preconfigured

• Explanation: The wireless network interface wlan0 is currently connected to a WiFi network using a connection profile named "preconfigured". This indicates that your Raspberry Pi is actively connected to a wireless network using this profile.

lo

• Type: loopback

• State: connected (externally)

• Connection: lo

• Explanation: The loopback interface (lo) is always considered connected. It's used by the system for internal communications (e.g., communicating with itself). "Connected (externally)" here indicates that it’s managed outside of the typical network management frameworks but still operational for its purposes.

docker0

• Type: bridge

• State: connected (externally)

• Connection: docker0

• Explanation: docker0 is a network bridge used by Docker to handle communications between Docker containers and the host machine. Similar to lo, "connected (externally)" suggests it’s managed by Docker and not directly by standard network management tools.

eth0

• Type: ethernet

• State: unavailable

• Connection: --

• Explanation: The Ethernet interface eth0 is marked as unavailable, which means there is no Ethernet cable connected or the interface is not configured/activated, making it not ready for use.

Which Network Interface to use?

To set up a static IP address on your Raspberry Pi, you should choose the network interface that is actively connected to the network and that you typically use to communicate over your network.

Based on our configuration, the best candidate is:

• wlan0

  • Type: wifi (Wireless LAN interface)

  • State: connected

  • Connection: preconfigured

Reasons to Choose wlan0

1. Active Connection: It is currently connected to a WiFi network, which means it's actively being used to connect your Raspberry Pi to the network.

2. WiFi Access: As it's a WiFi connection, setting a static IP address can be particularly useful if you frequently connect to this Raspberry Pi remotely, as WiFi-assigned IPs can change more frequently due to the dynamic nature of DHCP allocations by routers.

Modify Network Connections Using nmcli

Then, let's find the name of the connection you want to configure. Again use the command:

nmcli device status

The output

NAME                UUID                                  TYPE      DEVICE
preconfigured       8c6e2331-08f0-4e8e-a392-710af4dc3e5c  wifi      wlan0
lo                  12d503fa-b077-41fb-a0b4-4229c0a9cdfa  loopback  lo
docker0             b3300958-c4e3-4d75-826f-7c787a2070ed  bridge    docker0
Wired connection 1  c2e4dd17-2c70-35cf-a746-151f5ba9d0f6  ethernet  --

We have decided to configure the wireless connection and its default name is 'preconfigured'

NAME                UUID                                  TYPE      DEVICE
preconfigured       8c6e2331-08f0-4e8e-a392-710af4dc3e5c  wifi      wlan0

Gateway IP Address ([router-ip])

• Find the IP address of your network's gateway (router).

• It is usually the first IP address in your network's range.

• Example: 192.168.1.1

This is how we identify the default network interface and gateway

ip r | grep default

This command will show the default gateway used by the Raspberry Pi and the interface it is connected through, such as eth0 for Ethernet or wlan0 for Wi-Fi.

Example Output

The response from the command ip r | grep default executed on your Raspberry Pi gives information about the default gateway and the network interface configuration for your device. Let's break down the output:

default via 192.168.68.1 dev wlan0 proto dhcp src 192.168.68.67 metric 600

Explanation of Each Part:

• default: This indicates that this entry in the routing table is for the default route. The default route is used when no other route matches the destination IP of the packets. Essentially, it's the gateway through which the Raspberry Pi sends all traffic directed to destinations not in its local network.

• via 192.168.68.1: This part tells you the IP address of the default gateway. All traffic that doesn’t match a more specific route will be sent through this gateway. In this case, 192.168.68.1 is the router or another networking device in your network that provides access to the Internet or other networks.

• dev wlan0: This specifies the network device used for this route. Here, wlan0 indicates that the wireless network interface (typically Wi-Fi) is used for connecting to the network. It's the interface through which the Raspberry Pi connects to the default gateway.

• proto dhcp: This indicates that the IP address configuration on wlan0 is obtained via DHCP (Dynamic Host Configuration Protocol). DHCP is a network management protocol used on IP networks whereby a server dynamically assigns an IP address and other network configuration parameters to each device on the network, so they can communicate with other IP networks.

• src 192.168.68.67: This shows the source IP address that the Raspberry Pi uses when it sends packets out through wlan0. This would be the IP address assigned to your Raspberry Pi by the DHCP server (likely your router).

• metric 600: The metric is a value used by the IP routing protocol to determine the preference for using this route. The lower the metric, the higher the preference. In the context of multiple routes to a destination, a route with a lower metric is preferred. The metric can be important in systems with multiple network interfaces or multiple gateways; it helps in deciding which route is most efficient or quickest.

This output provides a concise overview of how the Raspberry Pi connects to other networks, particularly how it is configured to access the internet or other networks outside of its local subnet. It is crucial for troubleshooting network connectivity issues or for configuring network-related services on your device.

Here is the output from our Raspberry Pi

default via 192.168.68.1 dev wlan0 proto dhcp src 192.168.68.67 metric 600

This indicates that your default gateway IP address is 192.168.68.1.

This is the IP address of the router your Raspberry Pi communicates with for accessing networks outside your local network, such as the internet.

dev wlan0: This specifies that the network device used for this connection is wlan0, which is typically a WiFi interface on the Raspberry Pi.

proto dhcp: This tells you that the IP address was assigned via DHCP (Dynamic Host Configuration Protocol), which means the IP configuration is dynamically assigned by your network's DHCP server (usually your router).

src 192.168.68.67: This is the current IP address assigned to your Raspberry Pi on the network.

DNS Server IP Address

DNS Server IP Address ([dns-ip]):

• Determine the IP address of your DNS server.

• You can use the IP address of your router if it acts as a DNS server, or you can use public DNS servers like Google's DNS (8.8.8.8 or 8.8.4.4).

• Example: 192.168.1.1 or 8.8.8.8

Using NetworkManager you can use the nmcli command to find DNS settings:

nmcli dev show wlan0 | grep 'IP4.DNS'

This command will output the DNS servers configured for the wlan0 interface.

IP4.DNS[1]:                             202.142.142.142
IP4.DNS[2]:                             202.142.142.242

The command nmcli dev show wlan0 | grep 'IP4.DNS' does the following:

nmcli dev show wlan0: This command is used to display detailed information about the network device named wlan0, which is typically the wireless network interface.

|: This is the pipe symbol, which is used to pass the output of the previous command as input to the next command.

grep 'IP4.DNS': The grep command is used to search for specific patterns within the output. In this case, it searches for the pattern 'IP4.DNS' in the output of the nmcli dev show wlan0 command.

IP4.DNS[1]: 202.142.142.142
IP4.DNS[2]: 202.142.142.242

These lines indicate the DNS (Domain Name System) server IP addresses that are currently assigned to the wlan0 interface. In this case, there are two DNS servers configured:

• IP4.DNS[1]: The first DNS server has the IP address 202.142.142.142.

• IP4.DNS[2]: The second DNS server has the IP address 202.142.142.242.

These DNS server IP addresses are used by the system to resolve domain names to their corresponding IP addresses when accessing network resources or browsing the internet.

By using the nmcli dev show command with grep, you can quickly retrieve specific information about a network interface, such as the assigned DNS servers, without displaying all the other details provided by nmcli.

DNS Search Domain

The DNS search domain is a configuration parameter that specifies the default domain name to be appended to unqualified hostnames during DNS resolution. It is used to simplify accessing hosts within the same domain.

When a DNS search domain is set, and you try to access a hostname without specifying its fully qualified domain name (FQDN), the system will automatically append the search domain to the hostname and attempt to resolve it.

For example, if the DNS search domain is set to example.com, and you try to access a host named server1, the system will first try to resolve server1.example.com instead of just server1.

To find the current DNS search domain configured on your system using Network Manager, you can use the following command:

bashCopy codenmcli con show "Connection Name" | grep 'ipv4.dns-search'

Replace "Connection Name" with the actual name of the connection you want to check.

If the DNS search domain is configured, the output will show a line like:

Copy codeipv4.dns-search: example.com

The importance of the DNS search domain depends on your network setup and requirements:

1. If your network uses a specific domain name, setting the DNS search domain can make it easier to access hosts within that domain without typing the full FQDN every time.

2. In corporate or organizational networks, the DNS search domain is often set to the company's domain name to facilitate internal host resolution.

3. For home networks or standalone systems, the DNS search domain may not be as important, especially if you always use FQDNs or IP addresses to access hosts.

If you don't have a specific domain name for your network or don't need the automatic domain appending feature, you can leave the DNS search domain blank or unconfigured.

Keep in mind that the DNS search domain setting is connection-specific in Network Manager, so you may have different search domains configured for different connections (e.g., Ethernet, Wi-Fi, VPN).

In summary, the DNS search domain is a configuration parameter that helps with resolving unqualified hostnames by appending a default domain name. Its importance depends on your network setup and naming conventions. You can find the current DNS search domain using the nmcli command and grep for 'ipv4.dns-search'.

Once you have the connection name, modify its settings

nmcli con mod "Connection Name" ipv4.addresses [your-static-ip]/24 ipv4.gateway [router-ip] ipv4.dns [dns-ip] ipv4.dns-search [dns-search-domain] ipv4.method manual

[your-static-ip] - 192.168.68.67

[router-ip] - 192.168.68.1

[dns-ip] - 202.142.142.142

[dns-search-domain] Not relevant

Based on the information you provided, you can use the following command to configure the static IP address using Network Manager:

sudo nmcli con mod "will-wifi" ipv4.addresses 192.168.68.67/24 ipv4.gateway 192.168.68.1 ipv4.dns 202.142.142.142 ipv4.method manual

We will replace "Connection Name" with "will-wifi' -which is the actual name of the connection you want to modify.

You can find the connection name by running nmcli connection show.

Here's a breakdown of the command:

• nmcli con mod: This command is used to modify an existing network connection.

• "Connection Name": Replace this with the actual name of the connection you want to modify - 'will-wifi'.

• ipv4.addresses 192.168.68.67/24: This sets the static IP address to 192.168.68.67 with a subnet mask of /24 (equivalent to 255.255.255.0).

• ipv4.gateway 192.168.68.1: This sets the gateway IP address to 192.168.68.1.

• ipv4.dns 202.142.142.142: This sets the DNS server IP address to 202.142.142.142.

• ipv4.method manual: This sets the IPv4 configuration method to manual, indicating that you want to use a static IP address.

Note that you haven't provided a value for [dns-search-domain], so I haven't included the ipv4.dns-search option in the command. If you have a specific DNS search domain you want to use, you can add it to the command like this:

nmcli con mod "will-wifi" ipv4.addresses 192.168.68.67/24 ipv4.gateway 192.168.68.1 ipv4.dns 202.142.142.142 ipv4.dns-search example.com ipv4.method manual

After running the command, the static IP configuration will be applied to the specified connection.

To activate the changes, you can either bring the connection down and up again:

sudo nmcli con down "will-wifi"
sudo nmcli con up "will-wifi"

Or, you can reboot your system to ensure the changes take effect:

sudo reboot

After applying the changes, your device should have the specified static IP address (192.168.68.67) configured through Network Manager.

nmcli device status

The output

DEVICE         TYPE      STATE                   CONNECTION    
wlan0          wifi      connected               will-wifi  
lo             loopback  connected (externally)  lo         
docker0        bridge    connected (externally)  docker0    
p2p-dev-wlan0  wifi-p2p  disconnected            --         
end0           ethernet  unavailable             --           

Changing Connection Name

To change the connection name using Network Manager, you can use the nmcli command with the connection modify or connection edit option. Here's how you can change the connection name:

Using connection modify

nmcli connection modify "Old Connection Name" connection.id "New Connection Name"

Replace "Old Connection Name" with the current name of the connection you want to modify, and "New Connection Name" with the desired new name for the connection. For example, to rename the connection "preconfigured" to "will-wifi":

nmcli connection modify "preconfigured" connection.id "will-wifi"

Once you have gathered these details, you can modify the connection using the nmcli command:

nmcli con mod "will-wifi" ipv4.addresses 192.168.1.100/24 ipv4.gateway 192.168.1.1 ipv4.dns 192.168.1.1 ipv4.dns-search example.com ipv4.method manual

Make sure to replace "Connection Name" with the actual name of your connection and the placeholders with the corresponding values you found.

To apply the changes, you can either bring the connection down and up again:

nmcli con down "Connection Name"
nmcli con up "Connection Name"

Or, you can reboot your system to ensure the changes take effect:

sudo reboot

After applying the changes, your device should have the specified static IP address configured through Network Manager.

Check the IP Configuration

To verify the changes:

ip addr show

Restart NetworkManager Service

If you want to make sure all settings are correctly applied or need to refresh the NetworkManager:

sudo systemctl restart NetworkManager

Troubleshooting Tips

• Ensure that the connection name and parameters you use with nmcli match exactly what’s required for your network configuration.

• Use nmcli to list detailed information about a connection, which can help in troubleshooting:

nmcli con show "will-wifi"

• Sometimes changes might not take effect until the network service is restarted or the device is rebooted.

Verify the Configuration

After your Raspberry Pi reboots, check that the static IP address is correctly assigned:

hostname -I

You should see the static IP address you configured.

Conclusion

Setting a static IP address makes your Raspberry Pi accessible consistently at the same address, which is particularly useful for network applications like file servers or media centres.

By following these steps, you've ensured that your Raspberry Pi will retain the same IP address across reboots, making it easier to connect and manage remotely.