Using NetworkManager in Gentoo Linux

My current two laptops running Gentoo Linux (both with OpenRC, elogind, eudev and wpa_supplicant) use NetworkManager rather than Netifrc. (Actually, my desktop machines also use NetworkManager even though they are always connected to the same network.) NetworkManager has worked with wired and wireless networking on these laptops without any issues for over five years now. This post summarises how it is installed and configured.

I installed the package with the following USE flags enabled:

bluetooth dhclient elogind introspection modemmanager ncurses nss policykit ppp wext wifi

and the following USE flags disabled:

audit connection-sharing dhcpcd gnutls iwd json ofono ovs resolvconf selinux systemd teamd test vala

The precise status can be seen in the output of the eix command on my main laptop that uses Gentoo Stable:

root # eix -I net-misc/networkmanager
[I] net-misc/networkmanager
     Available versions:  [M]~1.22.10-r12^t 1.26.4^t ~1.26.6^t ~1.28.0-r1^t {audit bluetooth +concheck connection-sharing debug (+)dhclient dhcpcd elogind examples (+)gnutls gtk-doc (+)introspection iwd json libpsl lto (+)modemmanager ncurses (+)nss ofono ovs (+)policykit (+)ppp resolvconf selinux syslog systemd teamd test +tools vala (+)wext +wifi ABI_MIPS="n32 n64 o32" ABI_S390="32 64" ABI_X86="32 64 x32" KERNEL="linux"}
     Installed versions:  1.26.4^t(00:33:18 02/01/21)(bluetooth dhclient elogind introspection modemmanager ncurses nss policykit ppp wext wifi -audit -connection-sharing -dhcpcd -gnutls -iwd -json -ofono -ovs -resolvconf -selinux -systemd -teamd -test -vala ABI_MIPS="-n32 -n64 -o32" ABI_S390="-32 -64" ABI_X86="64 -32 -x32" KERNEL="linux")
     Homepage:            https://wiki.gnome.org/Projects/NetworkManager
     Description:         A set of co-operative tools that make networking simple and straightforward

I use network file systems, so I also configured the netmount service to run, and specified that NetworkManager is the network manager:

root # grep -v "^#\|^$" /etc/conf.d/netmount
rc_need="NetworkManager"

The network-related services that I configured to be started at boot are as follows:

root # rc-update show -v | grep -i net
       NetworkManager |      default
                local |      default nonetwork
           net-online |
         net.enp4s0f1 |
               net.lo |
             netmount |      default

(It is correct that net-online, net.enp4s0f1 and net.lo are not in any runlevel.)

Neither dhcpd nor dhcpcd services must be started at boot, as they would interfere with NetworkManager:

root # rc-update show -v | grep -i dhcp
               dhcpcd |   
                dhcpd |

By the way, if the output of the command ‘rc-update show -v‘ incudes non-existent physical interfaces not shown in the output of the ‘ifconfig‘ or ‘ip a‘ commands, you can delete the corresponding symlinks. For example, the only physical interfaces listed by the ifconfig command on my older laptop running Gentoo Linux Testing (~amd64) are eth0 and wlan0, but the ‘rc-update show -v‘ command originally showed many other interfaces, so I deleted them as follows:

root # cd /etc/init.d/
root # rm net.aol
root # rm net.ra*
root # rm net.ath*
root # rm net.eth[1,2,3,4,5,6,7,8]
root # rm net.ppp*
root # rm net.wlan[1,2,3]

The installation on that laptop is left with the correct symlinks:

root # ls -la /etc/init.d/net.*
lrwxrwxrwx 1 root root     6 Mar 30  2010 /etc/init.d/net.eth0 -> net.lo
-rwxr-xr-x 1 root root 19861 Feb 15 01:05 /etc/init.d/net.lo
lrwxrwxrwx 1 root root     6 Mar 30  2010 /etc/init.d/net.wlan0 -> net.lo

Anyway, coming back to my main laptop, all the services running in Gentoo Linux on it are shown below, for information:

root # rc-status
Runlevel: default
 dbus                                                       [  started  ]
 NetworkManager                                             [  started  ]
 netmount                                                   [  started  ]
 syslog-ng                                                  [  started  ]
 cupsd                                                      [  started  ]
 samba                                                      [  started  ]
 cronie                                                     [  started  ]
 clamd                                                      [  started  ]
 bluetooth                                                  [  started  ]
 xdm                                                        [  started  ]
 wsdd                                                       [  started  ]
 cups-browsed                                               [  started  ]
 sshd                                                       [  started  ]
 local                                                      [  started  ]
Dynamic Runlevel: hotplugged
Dynamic Runlevel: needed/wanted
 xdm-setup                                                  [  started  ]
 avahi-daemon                                               [  started  ]
Dynamic Runlevel: manual

I specified the laptop’s hostname in /etc/hosts, /etc/conf.d/hostname, /etc/hostname and /etc/dhcp/dhclient.conf:

root # grep -v "^#\|^$" /etc/hosts
127.0.0.1       clevow230ss     localhost
::1             clevow230ss     localhost
root # cat /etc/conf.d/hostname
# Set to the hostname of this machine
hostname="clevow230ss"
root # cat /etc/hostname
clevow230ss
root # grep -v "^#\|^$" /etc/dhcp/dhclient.conf
send host-name "clevow230ss";
supersede host-name "clevow230ss";

The purpose of the ‘supersede‘ statement in dhclient.conf is explained in man dhclient.conf(5):

supersede [ option declaration ] ;

If for some option the client should always use a locally-configured value or values rather than whatever is supplied by the server, these values can be defined in the supersede statement.

In other words, I do not want the hostname to be specified by a dhcp server (as this has caused problems for me in the past when connected to some networks).

I edited the configuration file /etc/NetworkManager/NetworkManager.conf to contain the following:

[main]
plugins=keyfile
rc-manager=none
dhcp=dhclient
no-auto-default=*

[keyfile]
hostname=clevow230ss

In earlier days it was necessary to specify the hostname in /etc/NetworkManager/NetworkManager.conf but that is no longer required. According to NetworkManager.conf(5) man page: ‘This key is deprecated and has no effect since the hostname is now stored in /etc/hostname or other system configuration files according to build options.’ I just left it in the file because it does no harm.

NetworkManager’s configuration files for your wired and wireless connections are normally created and edited by using the GUI network configuration tool (a.k.a. ‘front end’) in the Desktop Environment, such as plasma-nm and nm-applet, but can also be created/edited manually. For example, the NetworkManager file for my home Wi-Fi connection contains the following:

root # cat /etc/NetworkManager/system-connections/BT-5DF82T.nmconnection
[connection]
id=BT-5DF82T
uuid=3190e9d6-961f-38ab-fb90-1d323e6f35d2
type=wifi
autoconnect=false
permissions=

[wifi]
mac-address-blacklist=
mode=infrastructure
ssid=BT-5DF82T

[wifi-security]
key-mgmt=wpa-psk
psk-flags=1

[ipv4]
dns-search=
method=auto

[ipv6]
addr-gen-mode=stable-privacy
dns-search=
method=auto

NetworkManager generates the UUID automatically, but it could be generated manually (I have never bothered to do that):

The UUID values in the config files must be unique. You can use uuidgen command line tool to generate such values. Alternatively, you can leave out UUID entirely. In that case NetworkManager will generate a UUID based on the file name.

iwd (iNet Wireless Daemon)

Note that NetworkManager can be used with iwd instead of wpa_supplicant, although I have never bothered to try iwd, as NetworkManager with wpa_supplicant works fine on my laptops. If you want to try iwd instead of wpa_supplicant, NetworkManager will have to be installed with the iwd and introspection USE flags enabled, and you may have to make sure iwd is running before NetworkManager — see the following for further details:

About Fitzcarraldo
A Linux user with an interest in all things technical.

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