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Linux - Networking: Package NetworkManager

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• Linux - Networking: Package NetworkManager
  • NetworkManager Package
    • Configuration File
    • NetworkManager Utility
  • Lab: Enable/Disable Network Connectivity
  • Lab: Managing Devices
  • Lab: Manging Connection
  • Lab: Creating a Permanent Static IP Connection
  • Lab: Add/Delete a Secondary Static IP to a Connection
  • Lab: Configure Multiple Interfaces
    • List Adapters
    • Configure Interfaces
    • Configure Gateway and Priority
    • Configure Default DNS

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NetworkManager Package

• NetworkManager

  • a daemon that provides the default networking service in Linux.
• Package info:
  • dnf info NetworkManager
• File location:
  • /usr/sbin/NetworkManager
• Service
  • systemctl status NetworkManager
• Process
  • ps -ef | grep NetworkManager
• Tools to configure network manager
  • nmcli: Network manager command line interface
  • nmtui: Network manager text user interface
  • nm-connection-editor: Network manager GUI tool
  • GNOME Settings: GNOME desktop app.

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Configuration File

• Deprecated location:
  • /etc/sysconfig/network-scripts/
  • Previously, NetworkManager stored network profiles in ifcfg format in this directory
• Configuration File location:
  • /etc/NetworkManager
  • Network profiles in keyfile format in the directory:
    • /etc/NetworkManager/system-connections/

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NetworkManager Utility

• Retrieves network information: Does not required privilege.
• Configure networking: requires privileges.

• Ref:

  • https://people.freedesktop.org/~lkundrak/nm-docs/nmcli.html#property_aliases

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• Networking

CMD	DESC
nmcli general status	Display the overall status
nmcli networking	Display networking status
nmcli networking on	Enable networking
nmcli networking off	Disable networking

• Device

CMD	DESC
nmcli device status	Display status of devices (Default)
nmcli device show	Display detailed information about all devices.
nmcli device show device_name	Display a device detail infromation
nmcli device connect device_name	Connect the device with a suitable connection
nmcli device disconnect device_name	Disconnect a device and prevent the device from automatically activating
nmcli device delete device_name	Removes the interface (only works for software devices)

• Wi-Fi Networks

CMD	DESC
nmcli device wifi list	Scan and display nearby Wi-Fi networks
nmcli device wifi connect "SSID" password "password"	Connect to a Wi-Fi network
nmcli device disconnect device_name	Disconnect a Network

• Connection management

• NetworkManager Connections

  • a collection of data (Layer2 details, IP addressing, etc.) that describe how to create or connect to a network.
  • all network configurations

• Active Connection

  • a connection status when a device uses that connection’s configuration to create or connect to a network.
  • There may be multiple connections that apply to a device, but only one of them can be active on that device at any given time.
    • The additional connections can be used to allow quick switching between different networks and configurations.

CMD	DESC
nmcli connection show/nmcli c	Display the status of all connections
nmcli connection show "id_name"	Display details for specified connections
nmcli connection up "id_name"	Activate a connection
nmcli connection down "id_name"	Deactivate a connection
nmcli connection add con-name "id_name" ifname "if_name" type ethernet ip4 "ip/mask" gw4 "gw_ip"	Create a new connection
nmcli connection modify "id_name" ipv4.addresses "ip/mask" ipv4.gateway "gw_ip" ipv4.method manual	Modify ip address.
nmcli connection modify "id_name" ipv4.dns "dns_ip"	Modify DNS settings
nmcli connection delete "id_name"	Delete a Connection
nmcli connection reload "id_name"	Reload all connection files from disk.
nmcli connection reload filename	Load/reload connection files from disk.
nmcli connection export id_name	Export a connection.
nmcli connection import filename	Import an external/foreign configuration .

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Lab: Enable/Disable Network Connectivity

# Get overall networking status
nmcli general status
# STATE      CONNECTIVITY  WIFI-HW  WIFI     WWAN-HW  WWAN
# connected  full          missing  enabled  missing  enabled

# Disable networking
nmcli networking off
# STATE   CONNECTIVITY  WIFI-HW  WIFI     WWAN-HW  WWAN
# asleep  none          missing  enabled  missing  enabled

# Confirm networking status
nmcli networking
# disabled
nmcli networking connectivity
# none
nmcli general status
# STATE   CONNECTIVITY  WIFI-HW  WIFI     WWAN-HW  WWAN
# asleep  none          missing  enabled  missing  enabled

# Enable networking
nmcli networking on

# Verify
nmcli networking
# enabled
nmcli general status
# STATE      CONNECTIVITY  WIFI-HW  WIFI     WWAN-HW  WWAN
# connected  full          missing  enabled  missing  enabled
nmcli networking connectivity
# full

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Lab: Managing Devices

# get the status of all devices
nmcli device status
# DEVICE  TYPE      STATE                   CONNECTION
# ens160  ethernet  connected               ens161
# virbr0  bridge    connected (externally)  virbr0
# lo      loopback  unmanaged               --

# Add a new network adapter

# get new status
nmcli device status
# DEVICE  TYPE      STATE                   CONNECTION
# ens160  ethernet  connected               ens161
# virbr0  bridge    connected (externally)  virbr0
# ens224  ethernet  disconnected            --
# lo      loopback  unmanaged               --


# Get the detail info of a device
nmcli device show ens224
# GENERAL.DEVICE:                         ens224
# GENERAL.TYPE:                           ethernet
# GENERAL.HWADDR:                         00:0C:29:5B:CE:82
# GENERAL.MTU:                            1500
# GENERAL.STATE:                          30 (disconnected)
# GENERAL.CONNECTION:                     --
# GENERAL.CON-PATH:                       --
# WIRED-PROPERTIES.CARRIER:               on
# IP4.GATEWAY:                            --
# IP6.GATEWAY:                            --

# Connect a device
nmcli device connect ens224
# Device 'ens224' successfully activated with '6e3f82e8-2608-3d23-b02d-4cbd390003bb'.

# verify status
nmcli device status
# DEVICE  TYPE      STATE                   CONNECTION
# ens160  ethernet  connected               ens161
# ens224  ethernet  connected               Wired connection 1
# virbr0  bridge    connected (externally)  virbr0
# lo      loopback  unmanaged               --

# verify detail info
nmcli device show ens224
# GENERAL.DEVICE:                         ens224
# GENERAL.TYPE:                           ethernet
# GENERAL.HWADDR:                         00:0C:29:5B:CE:82
# GENERAL.MTU:                            1500
# GENERAL.STATE:                          100 (connected)
# GENERAL.CONNECTION:                     Wired connection 1
# GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/ActiveC>
# WIRED-PROPERTIES.CARRIER:               on
# IP4.ADDRESS[1]:                         192.168.204.159/24
# IP4.GATEWAY:                            192.168.204.2
# IP4.ROUTE[1]:                           dst = 192.168.204.0/24, nh = 0.0.0.0, m>
# IP4.ROUTE[2]:                           dst = 0.0.0.0/0, nh = 192.168.204.2, mt>
# IP4.DNS[1]:                             192.168.204.2
# IP4.DOMAIN[1]:                          localdomain
# IP6.ADDRESS[1]:                         fe80::c796:2422:9cde:9b61/64
# IP6.GATEWAY:                            --
# IP6.ROUTE[1]:                           dst = fe80::/64, nh = ::, mt = 1024

# verify ip address
hostname -I
# 192.168.204.153 192.168.122.1 192.168.204.159
# the 3rd one the ip of the new device

# disconnect
nmcli device disconnect ens224
# Device 'ens224' successfully disconnected.

# verify
nmcli device status
# DEVICE  TYPE      STATE                   CONNECTION
# ens160  ethernet  connected               ens161
# virbr0  bridge    connected (externally)  virbr0
# ens224  ethernet  disconnected            --
# lo      loopback  unmanaged               --

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Lab: Manging Connection

# Get all connections status
nmcli connection show
# NAME                UUID                                  TYPE      DEVICE
# ens161              bea1745d-c7f0-430a-a575-9c06f5d420a7  ethernet  ens160
# virbr0              157372ca-2156-4a35-b0e5-b7f4c3efb605  bridge    virbr0
# Wired connection 1  6e3f82e8-2608-3d23-b02d-4cbd390003bb  ethernet  --

# Get details for a specified connection
nmcli connection show "Wired connection 1"
# connection.id:                          Wired connection 1
# connection.uuid:                        6e3f82e8-2608-3d23-b02d-4cbd390003bb
# connection.stable-id:                   --
# connection.type:                        802-3-ethernet
# connection.interface-name:              ens224
# connection.autoconnect:                 yes
# connection.autoconnect-priority:        -999
# ...

# Delete a connection
nmcli connection delete "Wired connection 1"
# Connection 'Wired connection 1' (6e3f82e8-2608-3d23-b02d-4cbd390003bb) successfully deleted.

# verify
nmcli connection show
# NAME    UUID                                  TYPE      DEVICE
# ens161  bea1745d-c7f0-430a-a575-9c06f5d420a7  ethernet  ens160
# virbr0  157372ca-2156-4a35-b0e5-b7f4c3efb605  bridge    virbr0

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Lab: Creating a Permanent Static IP Connection

# Create a new connection
nmcli connection add con-name "static_con" type ethernet
# Connection 'static_con' (8bb06276-9ca1-4a9f-adc5-e2d02ac361ec) successfully added.

# confirm
nmcli connection show
# NAME        UUID                                  TYPE      DEVICE
# ens160      bea1745d-c7f0-430a-a575-9c06f5d420a7  ethernet  ens160
# virbr0      22dfb61f-7c71-44a3-87b2-4b95ebec61e2  bridge    virbr0
# static_con  8bb06276-9ca1-4a9f-adc5-e2d02ac361ec  ethernet  --

# Modify
# Specify an IP
nmcli connection modify "static_con" ipv4.addresses "192.168.204.170/24"
# Assign gateway IP
nmcli connection modify "static_con" ipv4.gateway "192.168.204.2"
# Set method as manual
nmcli connection modify "static_con" ipv4.method manual
# Set the dns ip
nmcli connection modify "static_con" ipv4.dns 8.8.8.8,8.8.4.4
# Set device
nmcli connection modify "static_con" ifname "ens224"

# Confirm configuration
nmcli connection show static_con
# ipv4.method:                            manual
# ipv4.dns:                               8.8.8.8,8.8.4.4
# ipv4.dns-search:                        --
# ipv4.dns-options:                       --
# ipv4.dns-priority:                      0
# ipv4.addresses:                         192.168.204.170/24
# ipv4.gateway:                           192.168.204.2
# ipv4.routes:                            --
# ipv4.route-metric:                      -1
# ipv4.route-table:                       0 (unspec)
# ipv4.routing-rules:                     --
# ipv4.ignore-auto-routes:                no
# ipv4.ignore-auto-dns:                   no
# ipv4.dhcp-client-id:                    --
# ipv4.dhcp-iaid:                         --
# ipv4.dhcp-timeout:                      0 (default)
# ipv4.dhcp-send-hostname:                yes
# ipv4.dhcp-hostname:                     --
# ipv4.dhcp-fqdn:                         --
# ipv4.dhcp-hostname-flags:               0x0 (none)
# ipv4.never-default:                     no
# ipv4.may-fail:                          yes
# ipv4.required-timeout:                  -1 (default)
# ipv4.dad-timeout:                       -1 (default)
# ipv4.dhcp-vendor-class-identifier:      --
# ipv4.link-local:                        0 (default)

# Activate a connecton
nmcli connection up static_con
# Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/6)

# Verify the connection is active
nmcli conn show
# NAME        UUID                                  TYPE      DEVICE
# ens160      bea1745d-c7f0-430a-a575-9c06f5d420a7  ethernet  ens160
# static_con  8bb06276-9ca1-4a9f-adc5-e2d02ac361ec  ethernet  ens224
# virbr0      22dfb61f-7c71-44a3-87b2-4b95ebec61e2  bridge    virbr0


# varify the IP of the device
ip addr show ens224
# 4: ens224: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
#     link/ether 00:0c:29:5b:ce:82 brd ff:ff:ff:ff:ff:ff
#     altname enp19s0
#     inet 192.168.204.170/24 brd 192.168.204.255 scope global noprefixroute ens224
#        valid_lft forever preferred_lft forever
#     inet6 fe80::70eb:5c8e:a06e:f8e2/64 scope link noprefixroute
#        valid_lft forever preferred_lft forever

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Lab: Add/Delete a Secondary Static IP to a Connection

• Adding a Secondary static IP to a Connection

# show the active connection
nmcli connection show --active
# NAME        UUID                                  TYPE      DEVICE
# ens160      bea1745d-c7f0-430a-a575-9c06f5d420a7  ethernet  ens160
# static_con  8bb06276-9ca1-4a9f-adc5-e2d02ac361ec  ethernet  ens224
# virbr0      22dfb61f-7c71-44a3-87b2-4b95ebec61e2  bridge    virbr0

# show the current ip
ip address show ens224 | grep "inet "
# inet 192.168.204.170/24 brd 192.168.204.255 scope global noprefixroute ens224

# modify a connection by adding a new ip
nmcli connection modify static_con +ipv4.addresses 192.168.204.171/24

# Confirm configuration
nmcli connection show static_con
# ipv4.method:                            manual
# ipv4.dns:                               8.8.8.8
# ipv4.dns-search:                        --
# ipv4.dns-options:                       --
# ipv4.dns-priority:                      0
# ipv4.addresses:                         192.168.204.170/24, 192.168.204.171/24
# ipv4.gateway:                           192.168.204.2
# ipv4.routes:                            --
# ipv4.route-metric:                      -1
# ipv4.route-table:                       0 (unspec)
# ipv4.routing-rules:                     --
# ipv4.ignore-auto-routes:                no
# ipv4.ignore-auto-dns:                   no
# ipv4.dhcp-client-id:                    --
# ipv4.dhcp-iaid:                         --
# ipv4.dhcp-timeout:                      0 (default)
# ipv4.dhcp-send-hostname:                yes
# ipv4.dhcp-hostname:                     --
# ipv4.dhcp-fqdn:                         --
# ipv4.dhcp-hostname-flags:               0x0 (none)

# reload the connection
nmcli connection reload
# same as down and up

# reboot
systemctl reboot

# verify
ip address show ens224 | grep "inet "
# inet 192.168.204.170/24 brd 192.168.204.255 scope global noprefixroute ens224
# inet 192.168.204.171/24 brd 192.168.204.255 scope global secondary noprefixroute ens224

• Removing a Secondary static IP to a Connection

# modify a connection by removing a new ip
nmcli connection modify static_con -ipv4.addresses 192.168.204.170/24

# Confirm configuration
nmcli connection show static_con
# ipv4.method:                            manual
# ipv4.dns:                               8.8.8.8
# ipv4.dns-search:                        --
# ipv4.dns-options:                       --
# ipv4.dns-priority:                      0
# ipv4.addresses:                         192.168.204.171/24
# ipv4.gateway:                           192.168.204.2
# ipv4.routes:                            --
# ipv4.route-metric:                      -1
# ipv4.route-table:                       0 (unspec)
# ipv4.routing-rules:                     --
# ipv4.ignore-auto-routes:                no
# ipv4.ignore-auto-dns:                   no
# ipv4.dhcp-client-id:                    --
# ipv4.dhcp-iaid:                         --
# ipv4.dhcp-timeout:                      0 (default)
# ipv4.dhcp-send-hostname:                yes
# ipv4.dhcp-hostname:                     --
# ipv4.dhcp-fqdn:                         --

# reload the connection
nmcli connection reload

# reboot
systemctl reboot

# verify
ip address show ens224 | grep "inet "
# inet 192.168.204.171/24 brd 192.168.204.255 scope global noprefixroute ens224

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Lab: Configure Multiple Interfaces

List Adapters

# list all interface
ip link show
# 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
#     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
# 2: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
#     link/ether 52:54:00:c5:c9:4d brd ff:ff:ff:ff:ff:ff
# 3: ens224: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
#     link/ether 00:0c:29:27:6b:f3 brd ff:ff:ff:ff:ff:ff
#     altname enp19s0
# 4: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
#     link/ether 00:0c:29:27:6b:fd brd ff:ff:ff:ff:ff:ff
#     altname enp3s0

nmcli d
# DEVICE  TYPE      STATE         CONNECTION
# ens160  ethernet  disconnected  --
# ens224  ethernet  disconnected  --
# virbr0  bridge    unmanaged     --
# lo      loopback  unmanaged     --

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Configure Interfaces

su -

# add ens160 connection
nmcli connection add con-name "ens160" type ethernet
nmcli connection modify ens160 ipv4.addresses 192.168.1.130/24
nmcli connection modify ens160 ipv4.method manual
nmcli connection modify ens160 ifname ens160
nmcli connection show ens160

# add ens224 connection
nmcli connection add con-name "ens224" type ethernet
nmcli connection modify ens224 ipv4.addresses 192.168.1.135/24
nmcli connection modify ens224 ipv4.method manual
nmcli connection modify ens224 ifname ens224

# enable connections
nmcli connection down ens160
nmcli connection up ens160
# Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/4)
nmcli connection down ens224
nmcli connection up ens224
# Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/5)

# confirm
nmcli c
# NAME    UUID                                  TYPE      DEVICE
# ens160  c6bae8b9-3866-47a6-8771-abc591b09bf7  ethernet  ens160
# ens224  5780461f-424b-49b2-9df5-a82106ac7c77  ethernet  ens224
nmcli d
# DEVICE  TYPE      STATE      CONNECTION
# ens160  ethernet  connected  ens160
# ens224  ethernet  connected  ens224
# virbr0  bridge    unmanaged  --
# lo      loopback  unmanaged  --

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Configure Gateway and Priority

nmcli c modify ens160 ipv4.gateway 192.168.1.2 ipv4.route-metric 100
nmcli c down ens160; nmcli c up ens160
# Connection 'ens160' successfully deactivated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/1)
# Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/3)

nmcli connection modify ens224 ipv4.gateway 192.168.1.2 ipv4.route-metric 200
nmcli c down ens224; nmcli c up ens224
# Connection 'ens224' successfully deactivated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/2)
# Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/4)

# confirm
ip route
# default via 192.168.1.2 dev ens160 proto static metric 100
# default via 192.168.1.2 dev ens224 proto static metric 200
# 192.168.1.0/24 dev ens160 proto kernel scope link src 192.168.1.130 metric 100
# 192.168.1.0/24 dev ens224 proto kernel scope link src 192.168.1.135 metric 200

# verify the default interface
ip route get 8.8.8.8
# 8.8.8.8 via 192.168.1.2 dev ens160 src 192.168.1.130 uid 0
    # cache

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Configure Default DNS

hostname
# serverhost

vi /etc/resolv.conf
# Generated by NetworkManager
# search serverhost
# nameserver 8.8.8.8

# restart nm
systemctl restart NetworkManager

# test
ping -c4 google.ca

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