NMCLI-EXAMPLES(7)

NAME
nmcli-examples - usage examples of nmcli

SYNOPSIS

nmcli [OPTIONS...]

DESCRIPTION

nmcli is a command-line client for NetworkManager. It allows controlling NetworkManager and reporting its status. For more information please refer to nmcli(1) manual page.

The purpose of this manual page is to provide you with various examples and usage scenarios of nmcli.

EXAMPLES

Example 1. Listing available Wi-Fi APs

    $ nmcli device wifi list
    *  SSID               MODE    CHAN  RATE       SIGNAL  BARS  SECURITY
       netdatacomm_local  Infra   6     54 Mbit/s  37      ▂▄__  WEP
    *  F1                 Infra   11    54 Mbit/s  98      ▂▄▆█  WPA1
       LoremCorp          Infra   1     54 Mbit/s  62      ▂▄▆_  WPA2 802.1X
       Internet           Infra   6     54 Mbit/s  29      ▂___  WPA1
       HPB110a.F2672A     Ad-Hoc  6     54 Mbit/s  22      ▂___  --
       Jozinet            Infra   1     54 Mbit/s  19      ▂___  WEP
       VOIP               Infra   1     54 Mbit/s  20      ▂___  WEP
       MARTINA            Infra   4     54 Mbit/s  32      ▂▄__  WPA2
       N24PU1             Infra   7     11 Mbit/s  22      ▂___  --
       alfa               Infra   1     54 Mbit/s  67      ▂▄▆_  WPA2
       bertnet            Infra   5     54 Mbit/s  20      ▂___  WPA1 WPA2

This command shows how to list available Wi-Fi networks (APs). You can also use --fields option for displaying different columns. nmcli -f all dev wifi list will show all of them.

Example 2. Connect to a password-protected wifi network

    $ nmcli device wifi connect "$SSID" password "$PASSWORD"

    $ nmcli --ask device wifi connect "$SSID"

Example 3. Showing general information and properties for a Wi-Fi interface

    $ nmcli -p -f general,wifi-properties device show wlan0
    ===========================================================================
                            Device details (wlan0)
    ===========================================================================
    GENERAL.DEVICE:           wlan0
    GENERAL.TYPE:             wifi
    GENERAL.VENDOR:           Intel Corporation
    GENERAL.PRODUCT:          PRO/Wireless 5100 AGN [Shiloh] Network Connection
    GENERAL.DRIVER:           iwlwifi
    GENERAL.DRIVER-VERSION:   3.8.13-100.fc17.x86_64
    GENERAL.FIRMWARE-VERSION: 8.83.5.1 build 33692
    GENERAL.HWADDR:           00:1E:65:37:A1:D3
    GENERAL.MTU:              1500
    GENERAL.STATE:            100 (connected)
    GENERAL.REASON:           0 (No reason given)
    GENERAL.UDI:              /sys/devices/pci0000:00/0000:00:1c.1/net/wlan0
    GENERAL.IP-IFACE:         wlan0
    GENERAL.IS-SOFTWARE:      no
    GENERAL.NM-MANAGED:       yes
    GENERAL.AUTOCONNECT:      yes
    GENERAL.FIRMWARE-MISSING: no
    GENERAL.CONNECTION:       My Alfa WiFi
    GENERAL.CON-UUID:         85194f4c-d496-4eec-bae0-d880b4cbcf26
    GENERAL.CON-PATH:         /org/freedesktop/NetworkManager/ActiveConnection/
    10
    ---------------------------------------------------------------------------
    WIFI-PROPERTIES.WEP:      yes
    WIFI-PROPERTIES.WPA:      yes
    WIFI-PROPERTIES.WPA2:     yes
    WIFI-PROPERTIES.TKIP:     yes
    WIFI-PROPERTIES.CCMP:     yes
    WIFI-PROPERTIES.AP:       no
    WIFI-PROPERTIES.ADHOC:    yes
    ---------------------------------------------------------------------------

This command shows information about a Wi-Fi device.

Example 4. Listing NetworkManager polkit permissions

    $ nmcli general permissions
    PERMISSION                                                VALUE
    org.freedesktop.NetworkManager.enable-disable-network     yes
    org.freedesktop.NetworkManager.enable-disable-wifi        yes
    org.freedesktop.NetworkManager.enable-disable-wwan        yes
    org.freedesktop.NetworkManager.enable-disable-wimax       yes
    org.freedesktop.NetworkManager.sleep-wake                 no
    org.freedesktop.NetworkManager.network-control            yes
    org.freedesktop.NetworkManager.wifi.share.protected       yes
    org.freedesktop.NetworkManager.wifi.share.open            yes
    org.freedesktop.NetworkManager.settings.modify.system     yes
    org.freedesktop.NetworkManager.settings.modify.own        yes
    org.freedesktop.NetworkManager.settings.modify.hostname   auth
    org.freedesktop.NetworkManager.settings.modify.global-dns auth
    org.freedesktop.NetworkManager.reload                     auth

This command shows configured polkit permissions for various NetworkManager operations. These permissions or actions (using polkit language) are configured by a system administrator and are not meant to be changed by users. The usual place for the polkit configuration is /usr/share/polkit-1/actions/org.freedesktop.NetworkManager.policy. pkaction command can display description for polkit actions.

      pkaction --action-id org.freedesktop.NetworkManager.network-control --verbose

More information about polkit can be found at http://www.freedesktop.org/wiki/Software/polkit.

Example 5. Listing NetworkManager log level and domains

    $ nmcli general logging
    LEVEL  DOMAINS
    INFO   PLATFORM,RFKILL,ETHER,WIFI,BT,MB,DHCP4,DHCP6,PPP,WIFI_SCAN,IP4,IP6,A
    UTOIP4,DNS,VPN,SHARING,SUPPLICANT,AGENTS,SETTINGS,SUSPEND,CORE,DEVICE,OLPC,
    WIMAX,INFINIBAND,FIREWALL,ADSL,BOND,VLAN,BRIDGE,DBUS_PROPS,TEAM,CONCHECK,DC
    B,DISPATCH

This command shows current NetworkManager logging status.

Example 6. Changing NetworkManager logging

    $ nmcli g log level DEBUG domains CORE,ETHER,IP
    $ nmcli g log level INFO domains DEFAULT

The first command makes NetworkManager log in DEBUG level, and only for CORE, ETHER and IP domains. The second command restores the default logging state. Please refer to the NetworkManager.conf(5) manual page for available logging levels and domains.

Example 7. Activating a VPN connection profile requiring interactive password input

    $ nmcli --ask con up my-vpn-con

This command activates a VPN connection profile enabling nmcli to interact with the user ('--ask'): this will allow nmcli to prompt for the VPN password on the command line when the password-flags are set to '0x02' ('always ask', see nm-settings-nmcli(5) ). This is particularly useful for OTP based VPNs, as the user needs to be prompted for the password each time the connection is activated.

Example 8. Adding a bonding master and two slave connection profiles

    $ nmcli con add type bond ifname mybond0 mode active-backup
    $ nmcli con add type ethernet ifname eth1 master mybond0
    $ nmcli con add type ethernet ifname eth2 master mybond0

This example demonstrates adding a bond master connection and two slaves. The first command adds a master bond connection, naming the bonding interface mybond0 and using active-backup mode. The next two commands add slaves connections, both enslaved to mybond0. The first slave will be bound to eth1 interface, the second to eth2.

Example 9. Adding a team master and two slave connection profiles

    $ nmcli con add type team con-name Team1 ifname Team1 config team1-master-json.conf
    $ nmcli con add type ethernet con-name Team1-slave1 ifname em1 master Team1
    $ nmcli con add type ethernet con-name Team1-slave2 ifname em2 master Team1

This example demonstrates adding a team master connection profile and two slaves. It is very similar to the bonding example. The first command adds a master team profile, naming the team interface and the profile Team1. The team configuration for the master is read from team1-master-json.conf file. Later, you can change the configuration with modify command (nmcli con modify Team1 team.config team1-master-another-json.conf). The last two commands add slaves profiles, both enslaved to Team1. The first slave will be bound to the em1 interface, the second to em2. The slaves don't specify config and thus teamd will use its default configuration. You will activate the whole setup by activating both slaves:

      $ nmcli con up Team1-slave1
      $ nmcli con up Team1-slave2

By default, the created profiles are marked for auto-activation. But if another connection has been activated on the device, the new profile won't activate automatically and you need to activate it manually.

Example 10. Adding a bridge and two slave profiles

    $ nmcli con add type bridge con-name TowerBridge ifname TowerBridge
    $ nmcli con add type ethernet con-name br-slave-1 ifname ens3 master TowerBridge
    $ nmcli con add type ethernet con-name br-slave-2 ifname ens4 master TowerBridge
    $ nmcli con modify TowerBridge bridge.stp no

This example demonstrates adding a bridge master connection and two slaves. The first command adds a master bridge connection, naming the bridge interface and the profile as TowerBridge. The next two commands add slaves profiles, both will be enslaved to TowerBridge. The first slave will be tied to ens3 interface, the second to ens4. The last command will disable 802.1D STP for the TowerBridge profile.

Example 11. Adding an ethernet connection profile with manual IP configuration

    $ nmcli con add con-name my-con-em1 ifname em1 type ethernet \
      ip4 192.168.100.100/24 gw4 192.168.100.1 ip4 1.2.3.4 ip6 abbe::cafe
    $ nmcli con mod my-con-em1 ipv4.dns "8.8.8.8 8.8.4.4"
    $ nmcli con mod my-con-em1 +ipv4.dns 1.2.3.4
    $ nmcli con mod my-con-em1 ipv6.dns "2001:4860:4860::8888 2001:4860:4860::8844"
    $ nmcli -p con show my-con-em1

The first command adds an Ethernet connection profile named my-con-em1 that is bound to interface name em1. The profile is configured with static IP addresses. Three addresses are added, two IPv4 addresses and one IPv6. The first IP 192.168.100.100 has a prefix of 24 (netmask equivalent of 255.255.255.0). Gateway entry will become the default route if this profile is activated on em1 interface (and there is no connection with higher priority). The next two addresses do not specify a prefix, so a default prefix will be used, i.e. 32 for IPv4 and 128 for IPv6. The second, third and fourth commands modify DNS parameters of the new connection profile. The last con show command displays the profile so that all parameters can be reviewed.

Example 12. Convenient field values retrieval for scripting

    $ nmcli -g ip4.address connection show my-con-eth0
    192.168.1.12/24

    $ nmcli -g ip4.address,ip4.dns connection show my-con-eth0
    192.168.1.12/24
    192.168.1.1

    $ nmcli -g ip4 connection show my-con-eth0
    IP4:192.168.1.12/24:192.168.1.1::192.168.1.1::

This example shows retrieval of ip4 connection field values via the --get-values option. Multiple comma separated fields can be provided: they will be printed one per line. If a whole section is provided instead of a single field, the name of the section will be printed followed by all the related field values on the same line. See also --terse, --mode, --fields and --escape options in nmcli(1) manual page for more customized output.

Example 13. Adding an Ethernet connection and configuring SR-IOV VFs

    $ nmcli con add type ethernet con-name EthernetPF ifname em1
    $ nmcli con modify EthernetPF sriov.total-vfs 3 sriov.autoprobe-drivers false
    $ nmcli con modify EthernetPF sriov.vfs '0 mac=00:11:22:33:44:55 vlans=10, 1 trust=true spoof-check=false'
    $ nmcli con modify EthernetPF +sriov.vfs '2 max-tx-rate=20'

This example demonstrates adding an Ethernet connection for physical function (PF) ens4 and configuring 3 SR-IOV virtual functions (VFs) on it. The first VF is configured with MAC address 00:11:22:33:44:55 and VLAN 10, the second one has the trust and spoof-check features respectively enabled and disabled. VF number 2 has a maximum transmission rate of 20Mbps. The kernel is instructed to not automatically instantiate a network interface for the VFs.

Example 14. Escaping colon characters in tabular mode

    $ nmcli -t -f general -e yes -m tab dev show eth0
    GENERAL:eth0:ethernet:Intel Corporation:82567LM Gigabit Network Connection:
    e1000e:2.1.4-k:1.8-3:00\:22\:68\:15\:29\:21:1500:100 (connected):0 (No reas
    on given):/sys/devices/pci0000\:00/0000\:00\:19.0/net/eth0:eth0:yes:yes:no:
    ethernet-13:89cbcbc6-dc85-456c-9c8b-bd828fee3917:/org/freedesktop/NetworkMa
    nager/ActiveConnection/9

This example shows escaping colon characters in tabular mode. It may be useful for script processing, because ':' is used as a field separator.

Example 15. nmcli usage in a NetworkManager dispatcher script to make Ethernet and Wi-Fi mutually exclusive

    #!/bin/bash
    export LC_ALL=C
    enable_disable_wifi ()
    {
        result=$(nmcli dev | grep "ethernet" | grep -w "connected")
        if [ -n "$result" ]; then
            nmcli radio wifi off
        else
            nmcli radio wifi on
        fi
    }
    if [ "$2" = "up" ]; then
        enable_disable_wifi
    fi
    if [ "$2" = "down" ]; then
        enable_disable_wifi
    fi

This dispatcher script makes Wi-Fi mutually exclusive with wired networking. When a wired interface is connected, Wi-Fi will be set to airplane mode (rfkilled). When the wired interface is disconnected, Wi-Fi will be turned back on. Name this script e.g. 70-wifi-wired-exclusive.sh and put it into /etc/NetworkManager/dispatcher.d/ directory. See NetworkManager(8) manual page for more information about NetworkManager dispatcher scripts.

Example sessions of interactive connection editor

Example 16. Adding an ethernet connection profile in interactive editor (a)

    $ nmcli connection edit type ethernet
    ===| nmcli interactive connection editor |===
    Adding a new '802-3-ethernet' connection
    Type 'help' or '?' for available commands.
    Type 'describe [<setting>.<prop>]' for detailed property description.
    You may edit the following settings: connection, 802-3-ethernet (ethernet),
    802-1x, ipv4, ipv6, dcb
    nmcli> print
    ===========================================================================
                              Connection details
    ===========================================================================
    connection.id:                      ethernet-4
    connection.uuid:                    de89cdeb-a3e1-4d53-8fa0-c22546c775f4
    connection.interface-name:          --
    connection.type:                    802-3-ethernet
    connection.autoconnect:             yes
    connection.autoconnect-priority:    0
    connection.timestamp:               0
    connection.read-only:               no
    connection.permissions:
    connection.zone:                    --
    connection.master:                  --
    connection.slave-type:              --
    connection.secondaries:
    connection.gateway-ping-timeout:    0
    ---------------------------------------------------------------------------
    802-3-ethernet.port:                --
    802-3-ethernet.speed:               0
    802-3-ethernet.duplex:              --
    802-3-ethernet.auto-negotiate:      yes
    802-3-ethernet.mac-address:         --
    802-3-ethernet.cloned-mac-address:  --
    802-3-ethernet.mac-address-blacklist:
    802-3-ethernet.mtu:                 auto
    802-3-ethernet.s390-subchannels:
    802-3-ethernet.s390-nettype:        --
    802-3-ethernet.s390-options:
    ---------------------------------------------------------------------------
    ipv4.method:                        auto
    ipv4.dns:
    ipv4.dns-search:
    ipv4.addresses:
    ipv4.gateway:                       --
    ipv4.routes:
    ipv4.route-metric:                  -1
    ipv4.ignore-auto-routes:            no
    ipv4.ignore-auto-dns:               no
    ipv4.dhcp-client-id:                --
    ipv4.dhcp-send-hostname:            yes
    ipv4.dhcp-hostname:                 --
    ipv4.never-default:                 no
    ipv4.may-fail:                      yes
    ---------------------------------------------------------------------------
    ipv6.method:                        auto
    ipv6.dns:
    ipv6.dns-search:
    ipv6.addresses:
    ipv6.gateway:                       --
    ipv6.routes:
    ipv6.route-metric:                  -1
    ipv6.ignore-auto-routes:            no
    ipv6.ignore-auto-dns:               no
    ipv6.never-default:                 no
    ipv6.may-fail:                      yes
    ipv6.ip6-privacy:                   -1 (unknown)
    ipv6.dhcp-hostname:                 --
    ---------------------------------------------------------------------------
    nmcli> goto ethernet
    You may edit the following properties: port, speed, duplex, auto-negotiate,
     mac-address, cloned-mac-address, mac-address-blacklist, mtu, s390-subchann
    els, s390-nettype, s390-options
    nmcli 802-3-ethernet> set mtu 1492
    nmcli 802-3-ethernet> b
    nmcli> goto ipv4.addresses
    nmcli ipv4.addresses> desc
    === [addresses] ===
    [NM property description]
    Array of IP addresses.
    [nmcli specific description]
    Enter a list of IPv4 addresses formatted as:
      ip[/prefix], ip[/prefix],...
    Missing prefix is regarded as prefix of 32.
    Example: 192.168.1.5/24, 10.0.0.11/24
    nmcli ipv4.addresses> set 192.168.1.100/24
    Do you also want to set 'ipv4.method' to 'manual'? [yes]: yes
    nmcli ipv4.addresses>
    nmcli ipv4.addresses> print
    addresses: 192.168.1.100/24
    nmcli ipv4.addresses> back
    nmcli ipv4> b
    nmcli> set ipv4.gateway 192.168.1.1
    nmcli> verify
    Verify connection: OK
    nmcli> print
    ===========================================================================
                              Connection details
    ===========================================================================
    connection.id:                      ethernet-4
    connection.uuid:                    de89cdeb-a3e1-4d53-8fa0-c22546c775f4
    connection.interface-name:          --
    connection.type:                    802-3-ethernet
    connection.autoconnect:             yes
    connection.autoconnect-priority:    0
    connection.timestamp:               0
    connection.read-only:               no
    connection.permissions:
    connection.zone:                    --
    connection.master:                  --
    connection.slave-type:              --
    connection.secondaries:
    connection.gateway-ping-timeout:    0
    ---------------------------------------------------------------------------
    802-3-ethernet.port:                --
    802-3-ethernet.speed:               0
    802-3-ethernet.duplex:              --
    802-3-ethernet.auto-negotiate:      yes
    802-3-ethernet.mac-address:         --
    802-3-ethernet.cloned-mac-address:  --
    802-3-ethernet.mac-address-blacklist:
    802-3-ethernet.mtu:                 1492
    802-3-ethernet.s390-subchannels:
    802-3-ethernet.s390-nettype:        --
    802-3-ethernet.s390-options:
    ---------------------------------------------------------------------------
    ipv4.method:                        manual
    ipv4.dns:
    ipv4.dns-search:
    ipv4.addresses:                     192.168.1.100/24
    ipv4.gateway:                       192.168.1.1
    ipv4.routes:
    ipv4.route-metric:                  -1
    ipv4.ignore-auto-routes:            no
    ipv4.ignore-auto-dns:               no
    ipv4.dhcp-client-id:                --
    ipv4.dhcp-send-hostname:            yes
    ipv4.dhcp-hostname:                 --
    ipv4.never-default:                 no
    ipv4.may-fail:                      yes
    ---------------------------------------------------------------------------
    ipv6.method:                        auto
    ipv6.dns:
    ipv6.dns-search:
    ipv6.addresses:
    ipv6.routes:
    ipv6.route-metric:                  -1
    ipv6.ignore-auto-routes:            no
    ipv6.ignore-auto-dns:               no
    ipv6.never-default:                 no
    ipv6.may-fail:                      yes
    ipv6.ip6-privacy:                   -1 (unknown)
    ipv6.dhcp-hostname:                 --
    ---------------------------------------------------------------------------
    nmcli> set ipv4.dns 8.8.8.8 8.8.4.4
    nmcli> print
    ===========================================================================
                              Connection details
    ===========================================================================
    connection.id:                      ethernet-4
    connection.uuid:                    de89cdeb-a3e1-4d53-8fa0-c22546c775f4
    connection.interface-name:          --
    connection.type:                    802-3-ethernet
    connection.autoconnect:             yes
    connection.autoconnect-priority:    0
    connection.timestamp:               0
    connection.read-only:               no
    connection.permissions:
    connection.zone:                    --
    connection.master:                  --
    connection.slave-type:              --
    connection.secondaries:
    connection.gateway-ping-timeout:    0
    ---------------------------------------------------------------------------
    802-3-ethernet.port:                --
    802-3-ethernet.speed:               0
    802-3-ethernet.duplex:              --
    802-3-ethernet.auto-negotiate:      yes
    802-3-ethernet.mac-address:         --
    802-3-ethernet.cloned-mac-address:  --
    802-3-ethernet.mac-address-blacklist:
    802-3-ethernet.mtu:                 1492
    802-3-ethernet.s390-subchannels:
    802-3-ethernet.s390-nettype:        --
    802-3-ethernet.s390-options:
    ---------------------------------------------------------------------------
    ipv4.method:                        manual
    ipv4.dns:                           8.8.8.8,8.8.4.4
    ipv4.dns-search:
    ipv4.addresses:                     192.168.1.100/24
    ipv4.gateway:                       192.168.1.1
    ipv4.routes:
    ipv4.route-metric:                  -1
    ipv4.ignore-auto-routes:            no
    ipv4.ignore-auto-dns:               no
    ipv4.dhcp-client-id:                --
    ipv4.dhcp-send-hostname:            yes
    ipv4.dhcp-hostname:                 --
    ipv4.never-default:                 no
    ipv4.may-fail:                      yes
    ---------------------------------------------------------------------------
    ipv6.method:                        auto
    ipv6.dns:
    ipv6.dns-search:
    ipv6.addresses:
    ipv6.gateway:                       --
    ipv6.routes:
    ipv6.route-metric:                  -1
    ipv6.ignore-auto-routes:            no
    ipv6.ignore-auto-dns:               no
    ipv6.never-default:                 no
    ipv6.may-fail:                      yes
    ipv6.ip6-privacy:                   -1 (unknown)
    ipv6.dhcp-hostname:                 --
    ---------------------------------------------------------------------------
    nmcli> verify
    Verify connection: OK
    nmcli> save
    Connection 'ethernet-4' (de89cdeb-a3e1-4d53-8fa0-c22546c775f4) successfully
     saved.
    nmcli> quit

Example session in the nmcli interactive connection editor. The scenario creates an Ethernet connection profile with static addressing (IPs and DNS).

Example 17. Bluetooth connection profiles

NetworkManger supports both connecting to NAP and DUN devices as a client. It also supports sharing the network via a NAP server.

For NAP client connections, NetworkManager automatically creates a suitable in-memory profile for paired devices if none is available. You may use that generated profile directly, but you may also modify and persist it, which will prevent to automatically re-create it. You may also create a profile from scratch. For example, the following uses DHCP and IPv6 autoconf for address configuration:

    $ nmcli connection add type bluetooth con-name "Profile for My Bluetooth Device (NAP)" autoconnect no bluetooth.type panu bluetooth.bdaddr "$BDADDR"

For DUN connections, the user needs to configure modem settings and hence no profile gets created automatically. The modem settings depend on your device and you either need a "gsm" or a "csma" section. For example,

    $ nmcli connection add type bluetooth con-name "Profile for My Bluetooth Device (DUN)" autoconnect no bluetooth.type dun bluetooth.bdaddr "$BDADDR" gsm.apn apn.com

Finally, you can create a bluetooth hotspot. BlueZ implements those as a bridge device, so such profiles also have a bridge section. Also, you probably want to set IP methods as "shared", so that clients get automatic IP addressing. Note that the "shared" IPv4 method requires dnsmasq to be available.

    $ nmcli connection add type bluetooth con-name "My Bluetooth Hotspot" autoconnect no ifname btnap0 bluetooth.type nap ipv4.method shared ipv6.method shared

Example 18. Offline use

    $ nmcli --offline con add type ethernet '
      conn.id eth0 \
      conn.interface-name eth0 \
      >/sysroot/etc/NetworkManager/system-connections/eth0.nmconnection

Creates a connection file in keyfile format without using the NetworkManager service. This allows for use of familiar nmcli syntax in situations where the service is not running, such as during system installation of image provisioning and ensures the resulting file is correctly formatted.

    $ nmcli --offline con modify type ethernet '
      conn.id eth0-ipv6 \
      ipv4.method disabled \
      </sysroot/etc/NetworkManager/system-connections/eth0.nmconnection \
      >/sysroot/etc/NetworkManager/system-connections/eth0-ipv6.nmconnection

Read and write a connection file without using the NetworkManager service, modifying some properties along the way.

This allows templating of the connection profiles using familiar nmcli syntax in situations where the service is not running.

Example 19. Device Checkpoint and Restore

    $ nmcli dev checkpoint eth0 -- nmcli dev dis eth0
    Device 'eth0' successfully disconnected.
    Type "Yes" to commit the changes: No
    Checkpoint was removed.

In this example the device eth0 was disconnected with the eth0 checkpoint taken. The user didn't confirm that the change is good, so the eth0 was brought back to the state it was when the checkpoint was taken.

If the command being run unintentionaly brings down the remote connection (such as a ssh(1) session) to the very machine it's being run on, the user wouldn't be able to confirm the success and the connectivity would end up being restored after a timeout.

If, on the other hand, the command results in a success, the user could just confirm, causing the checkpoint to be abandoned without a rollback:

    $ nmcli dev checkpoint -- ip link del br0
    Type "Yes" to commit the changes: Yes

SEE ALSO

nmcli(1), NetworkManager(8), NetworkManager.conf(5), nm-settings-nmcli(5), nm-online(1), nm-applet(1), nm-connection-editor(1)