NetworkManager CLI Administration

Desktop users click the applet; admins script nmcli — same engine underneath.

Connection lifecycle

nmcli device status                  # interfaces + states
nmcli connection show                # saved profiles
nmcli connection add type ethernet ifname eth0 con-name office \
    ipv4.method manual ipv4.addresses 192.168.10.50/24 \
    ipv4.gateway 192.168.10.1 ipv4.dns "192.168.10.1 1.1.1.1"
nmcli connection up office
nmcli connection modify office connection.autoconnect yes
nmcli device wifi hotspot ssid acreet ssid-password supersecret   # instant AP!

DNS handling

Per-connection DNS beats editing resolv.conf (it’s generated!):

nmcli con mod office ipv4.ignore-auto-dns yes ipv4.dns "10.0.0.53"
nmcli con up office
resolvectl status | less             # per-link DNS view (systemd-resolved glue)

VLANs & bridges (libvirt friends)

sudo nmcli con add type bridge ifname br0 stp no
sudo nmcli con add type bridge-slave ifname enp3s0 master br0
sudo nmcli con up br0

Point virt-manager networks at br0 for real-LAN VMs (Virtual Machines on AcreetionOS).

Dispatcher: react to network events

/etc/NetworkManager/dispatcher.d/90-home-magic:

#!/bin/sh
IF="$1"; ACTION="$2"
[ "$ACTION" = up ] || exit 0
case "$(nmcli -t -f GENERAL.CONNECTION dev show "$IF")" in
  *home-wifi*) nmcli con down office-vpn ;;
esac

chmod +x it; runs as root on events (up/down/hostname…).

Headless servers

NetworkManager runs fine without desktop (shipped enabled): all above applies over SSH (OpenSSH Server Setup & Hardening). nmtui covers the quick-edit niche interactively.