The network
role enables users to configure network on the target machines.
This role can be used to configure:
- Ethernet interfaces
- Bridge interfaces
- Bonded interfaces
- VLAN interfaces
- MacVLAN interfaces
- Infiniband interfaces
- Wireless (WiFi) interfaces
- IP configuration
- 802.1x authentication
The network
role supports two providers: nm
and initscripts
. nm
is
used by default in RHEL7 and initscripts
in RHEL6. These providers can be
configured per host via the network_provider
variable. In
absence of explicit configuration, it is autodetected based on the
distribution. However, note that either nm
or initscripts
is not tied to a certain
distribution. The network
role works everywhere the required API is available.
This means that nm
requires at least NetworkManager's API version 1.2 available.
For initscripts
, the legacy network service is required as used in Fedora or RHEL.
For each host a list of networking profiles can be configured via the
network_connections
variable.
-
For
initscripts
, profiles correspond to ifcfg files in the/etc/sysconfig/network-scripts/ifcfg-*
directory. -
For
NetworkManager
, profiles correspond to connection profiles as handled by NetworkManager. Fedora and RHEL use theifcfg-rh-plugin
for NetworkManager, which also writes or reads configuration files to/etc/sysconfig/network-scripts/ifcfg-*
for compatibility.
Note that the network
role primarily operates on networking profiles
(connections) and not on devices, but it uses the profile name by default as
the interface name. It is also possible to create generic profiles, by creating
for example a profile with a certain IP configuration without activating the
profile. To apply the configuration to the actual networking interface, use the
nmcli
commands on the target system.
Warning: The network
role updates or creates all connection profiles on
the target system as specified in the network_connections
variable. Therefore,
the network
role removes options from the specified profiles if the options are
only present on the system but not in the network_connections
variable.
Exceptions are mentioned below.
The network
role is configured via variables starting with network_
as
the name prefix. List of variables:
network_provider
- Thenetwork_provider
variable allows to set a specific provider (nm
orinitscripts
) . Setting it to{{ network_provider_os_default }}
, the provider is set depending on the operating system. This is usuallynm
except for RHEL 6 or CentOS 6 systems. Changing the provider for an existing profile is not supported. To switch providers, it is recommended to first remove profiles with the old provider and then create new profiles with the new provider.network_connections
- The connection profiles are configured asnetwork_connections
, which is a list of dictionaries that include specific options.network_allow_restart
- Certain configurations require the role to restart network services. For example, if a wireless connection is configured and NetworkManager-wifi is not installed, NetworkManager must be restarted prior to the connection being configured. Setting this tono
will prevent the role from restarting network service.
Setting the variables
network_provider: nm
network_connections:
- name: eth0
#...
network_allow_restart: yes
The network_connections
variable is a list of dictionaries that include the
following options. List of options:
The name
option identifies the connection profile. It is not the name of the
networking interface for which the profile applies, though we can associate
the profile with an interface and give them the same name.
Note that you can have multiple profiles for the same device, but only
one profile can be active on the device each time.
For NetworkManager, a connection can only be active at one device each time.
-
For
NetworkManager
, thename
option corresponds to theconnection.id
property option. Although NetworkManager supports multiple connections with the sameconnection.id
, thenetwork
role cannot handle a duplicatename
. Specifying aname
multiple times refers to the same connection profile. -
For
initscripts
, thename
option determines the ifcfg file name/etc/sysconfig/network-scripts/ifcfg-$NAME
. Note that thename
does not specify theDEVICE
but a filename. As a consequence,'/'
is not a valid character for thename
.
You can also use the same connection profile multiple times. Therefore, it is possible to create a profile and activate it separately.
The state
option identifies what is the runtime state of each connection profile. The
state
option (optional) can be set to the following values:
up
- the connection profile is activateddown
- the connection profile is deactivated
-
For
NetworkManager
, this corresponds tonmcli connection id {{name}} up
. -
For
initscripts
, this corresponds toifup {{name}}
.
When the state
option is set to up
, you can also specify the wait
option (optional):
wait: 0
- initiates only the activation, but does not wait until the device is fully connected. The connection will be completed in the background, for example after a DHCP lease was received.wait: <seconds>
is a timeout that enables you to decide how long you give the device to activate. The default is using a suitable timeout. Note that thewait
option is only supported by NetworkManager.
Note that state: up
always re-activates the profile and possibly changes the
networking configuration, even if the profile was already active before. As
a consequence, state: up
always changes the system.
-
For
NetworkManager
, it corresponds tonmcli connection id {{name}} down
. -
For
initscripts
, it corresponds to callifdown {{name}}
.
You can deactivate a connection profile, even if is currently not active. As a
consequence, state: down
always changes the system.
Note that if the state
option is unset, the connection profile's runtime state will
not be changed.
The persistent_state
option identifies if a connection profile is persistent (saved on
disk). The persistent_state
option can be set to the following values:
Note that if persistent_state
is present
and the connection profile contains
the type
option, the profile will be created or updated. If the connection profile is
incomplete (no type
option), the behavior is undefined. Also, the present
value
does not directly result in a change in the network configuration. If the state
option
is not set to up
, the profile is only created or modified, not activated.
For NetworkManager, the new connection profile is created with the autoconnect
option enabled by default. Therefore, NetworkManager can activate the new
profile on a currently disconnected device. (rh#1401515).
The absent
value ensures that the profile is not present on the
target host. If a profile with the given name
exists, it will be deleted. In this case:
-
NetworkManager
deletes all connection profiles with the correspondingconnection.id
. Deleting a profile usually does not change the current networking configuration, unless the profile was currently activated on a device. Deleting the currently active connection profile disconnects the device. That makes the device eligible to autoconnect another connection (for more details, see rh#1401515). -
initscripts
deletes the ifcfg file in most cases with no impact on the runtime state of the system unless some component is watching the sysconfig directory.
Note: For profiles that only contain a state
option, the network
role only activates
or deactivates the connection without changing its configuration.
The type
option can be set to the following values:
ethernet
bridge
bond
team
vlan
macvlan
infiniband
wireless
If the type is ethernet
, then there can be an extra ethernet
dictionary with the following
items (options): autoneg
, speed
and duplex
, which correspond to the
settings of the ethtool
utility with the same name.
autoneg
:yes
(default) orno
[if auto-negotiation is enabled or disabled]speed
: speed in Mbit/sduplex
:half
orfull
Note that the speed
and duplex
link settings are required when autonegotiation is
disabled (autoneg: no
).
The bridge
, bond
, team
device types work similar. Note that team
is not
supported in RHEL6 kernels.
For ports, the port_type
and controller
properties must be set. Note that ports
should not have ip
settings.
The controller
refers to the name
of a profile in the Ansible
playbook. It is neither an interface-name nor a connection-id of
NetworkManager.
-
For NetworkManager,
controller
will be converted to theconnection.uuid
of the corresponding profile. -
For initscripts, the controller is looked up as the
DEVICE
from the corresponding ifcfg file.
As controller
refers to other profiles of the same or another play, the order of the
connections
list matters. Profiles that are referenced by other profiles need to be
specified first. Also, --check
ignores the value of the controller
and assumes it
will be present during a real run. That means, in presence of an invalid controller
,
--check
may signal success but the actual play run fails.
The team
type uses roundrobin
as the runner
configuration. No further
configuration is supported at the moment.
Similar to controller
, the parent
references the connection profile in the ansible
role.
Similar to controller
and vlan
, the parent
references the connection profile in
the ansible role.
The wireless
type supports WPA-PSK (password) authentication and WPA-EAP (802.1x)
authentication.
nm
(NetworkManager) is the only supported network_provider
for this type.
If WPA-EAP is used, ieee802_1x settings must be defined in the ieee802_1x option.
The following options are supported:
ssid
: the SSID of the wireless network (required)key_mgmt
:wpa-psk
orwpa-eap
(required)password
: password for the network (required ifwpa-psk
is used)
By default, profiles are created with autoconnect enabled.
-
For
NetworkManager
, this corresponds to theconnection.autoconnect
property. -
For
initscripts
, this corresponds to theONBOOT
property.
The mac
address is optional and restricts the profile to be usable only on
devices with the given MAC address. mac
is only allowed for type
ethernet
or infiniband
to match a non-virtual device with the
profile. The value of the mac
address needs to be specified in hexadecimal notation
using colons (for example: mac: "00:00:5e:00:53:5d"
). To avoid YAML parsing mac
addresses as integers in sexagesimal (base 60) notation (see
https://yaml.org/spec/1.1/#id858600), it is recommended to always quote the value
with double quotes and sometimes it is necessary.
-
For
NetworkManager
,mac
is the permanent MAC address,ethernet.mac-address
. -
For
initscripts
,mac
is the currently configured MAC address of the device (HWADDR
).
The mtu
option denotes the maximum transmission unit for the profile's
device. The maximum value depends on the device. For virtual devices, the
maximum value of the mtu
option depends on the underlying device.
For the ethernet
and infiniband
types, the interface_name
option restricts the
profile to the given interface by name. This argument is optional and by default the
profile name is used unless a mac address is specified using the mac
key. Specifying
an empty string (""
) means that the profile is not restricted to a network interface.
Note: With persistent interface naming,
the interface is predictable based on the hardware configuration.
Otherwise, the mac
address might be an option.
For virtual interface types such as bridges, the interface_name
is the name of the created
interface. In case of a missing interface_name
, the name
of the profile name is used.
Note: The name
(the profile name) and the interface_name
(the device name) may be
different or the profile may not be tied to an interface at all.
The zone
option sets the firewalld zone for the interface.
Ports to the bridge, bond or team devices cannot specify a zone.
The IP configuration supports the following options:
-
address
Manual addressing can be specified via a list of addresses under the
address
option. -
dhcp4
,auto6
, andipv6_disabled
Also, manual addressing can be specified by setting either
dhcp4
orauto6
. Thedhcp4
key is for DHCPv4 andauto6
for StateLess Address Auto Configuration (SLAAC). Note that thedhcp4
andauto6
keys can be omitted and the default key depends on the presence of manual addresses.ipv6_disabled
can be set to disable ipv6 for the connection. -
dhcp4_send_hostname
If
dhcp4
is enabled, it can be configured whether the DHCPv4 request includes the hostname via thedhcp4_send_hostname
option. Note thatdhcp4_send_hostname
is only supported by thenm
provider and corresponds toipv4.dhcp-send-hostname
property. -
dns
Manual DNS configuration can be specified via a list of addresses given in the
dns
option. -
dns_search
dns_search
is only supported for IPv4 nameservers. Manual DNS configuration can be specified via a list of domains to search given in thedns_search
option. -
dns_options
dns_options
is only supported for the NetworkManager provider and IPv4 nameservers. Manual DNS configuration via a list of DNS options can be given in thedns_options
. The list of supported DNS options for IPv4 nameservers is described in man 5 resolv.conf. Currently, the list of supported DNS options is:attempts:n
debug
edns0
ndots:n
no-check-names
no-reload
no-tld-query
rotate
single-request
single-request-reopen
timeout:n
trust-ad
use-vc
Note: The "trust-ad" setting is only honored if the profile contributes name servers to resolv.conf, and if all contributing profiles have "trust-ad" enabled. When using a caching DNS plugin (dnsmasq or systemd-resolved in NetworkManager.conf) then "edns0" and "trust-ad" are automatically added.
-
gateway4
andgateway6
The default gateway for IPv4 (
gateway4
) or IPv6 (gateway6
) packets. -
route_metric4
androute_metric6
For
NetworkManager
,route_metric4
androute_metric6
corresponds to theipv4.route-metric
andipv6.route-metric
properties, respectively. If specified, it determines the route metric for DHCP assigned routes and the default route, and thus the priority for multiple interfaces. -
route
Static route configuration can be specified via a list of routes given in the
route
option. The default value is an empty list. Each route is a dictionary with the following entries:network
,prefix
,gateway
andmetric
.network
andprefix
specify the destination network. Note that Classless inter-domain routing (CIDR) notation or network mask notation are not supported yet. -
route_append_only
The
route_append_only
option allows only to add new routes to the existing routes on the system.If the
route_append_only
boolean option is set toyes
, the specified routes are appended to the existing routes. Ifroute_append_only
is set tono
(default), the current routes are replaced. Note that settingroute_append_only
toyes
without settingroute
has the effect of preserving the current static routes. -
rule_append_only
The
rule_append_only
boolean option allows to preserve the current routing rules. Note that specifying routing rules is not supported yet.
Note: When route_append_only
or rule_append_only
is not specified, the network
role deletes the current routes or routing rules.
Note: Ports to the bridge, bond or team devices cannot specify ip
settings.
The ethtool settings allow to enable or disable various features. The names
correspond to the names used by the ethtool
utility. Depending on the actual
kernel and device, changing some options might not be supported.
The ethtool configuration supports the following options:
-
ring
Changes the
rx
/tx
ring
parameters of the specified network device. The list of supportedring
parameters is:rx
- Changes the number of ring entries for the Rx ring.rx-jumbo
- Changes the number of ring entries for the Rx Jumbo ring.rx-mini
- Changes the number of ring entries for the Rx Mini ring.tx
- Changes the number of ring entries for the Tx ring.
ethtool:
features:
esp_hw_offload: yes|no # optional
esp_tx_csum_hw_offload: yes|no # optional
fcoe_mtu: yes|no # optional
gro: yes|no # optional
gso: yes|no # optional
highdma: yes|no # optional
hw_tc_offload: yes|no # optional
l2_fwd_offload: yes|no # optional
loopback: yes|no # optional
lro: yes|no # optional
ntuple: yes|no # optional
rx: yes|no # optional
rx_all: yes|no # optional
rx_fcs: yes|no # optional
rx_gro_hw: yes|no # optional
rx_udp_tunnel_port_offload: yes|no # optional
rx_vlan_filter: yes|no # optional
rx_vlan_stag_filter: yes|no # optional
rx_vlan_stag_hw_parse: yes|no # optional
rxhash: yes|no # optional
rxvlan: yes|no # optional
sg: yes|no # optional
tls_hw_record: yes|no # optional
tls_hw_tx_offload: yes|no # optional
tso: yes|no # optional
tx: yes|no # optional
tx_checksum_fcoe_crc: yes|no # optional
tx_checksum_ip_generic: yes|no # optional
tx_checksum_ipv4: yes|no # optional
tx_checksum_ipv6: yes|no # optional
tx_checksum_sctp: yes|no # optional
tx_esp_segmentation: yes|no # optional
tx_fcoe_segmentation: yes|no # optional
tx_gre_csum_segmentation: yes|no # optional
tx_gre_segmentation: yes|no # optional
tx_gso_partial: yes|no # optional
tx_gso_robust: yes|no # optional
tx_ipxip4_segmentation: yes|no # optional
tx_ipxip6_segmentation: yes|no # optional
tx_nocache_copy: yes|no # optional
tx_scatter_gather: yes|no # optional
tx_scatter_gather_fraglist: yes|no # optional
tx_sctp_segmentation: yes|no # optional
tx_tcp_ecn_segmentation: yes|no # optional
tx_tcp_mangleid_segmentation: yes|no # optional
tx_tcp_segmentation: yes|no # optional
tx_tcp6_segmentation: yes|no # optional
tx_udp_segmentation: yes|no # optional
tx_udp_tnl_csum_segmentation: yes|no # optional
tx_udp_tnl_segmentation: yes|no # optional
tx_vlan_stag_hw_insert: yes|no # optional
txvlan: yes|no # optional
coalesce:
adaptive_rx: yes|no # optional
adaptive_tx: yes|no # optional
pkt_rate_high: 0 # optional mininum=0 maximum=0xffffffff
pkt_rate_low: 0 # optional mininum=0 maximum=0xffffffff
rx_frames: 0 # optional mininum=0 maximum=0xffffffff
rx_frames_high: 0 # optional mininum=0 maximum=0xffffffff
rx_frames_irq: 0 # optional mininum=0 maximum=0xffffffff
rx_frames_low: 0 # optional mininum=0 maximum=0xffffffff
rx_usecs: 0 # optional mininum=0 maximum=0xffffffff
rx_usecs_high: 0 # optional mininum=0 maximum=0xffffffff
rx_usecs_irq: 0 # optional mininum=0 maximum=0xffffffff
rx_usecs_low: 0 # optional mininum=0 maximum=0xffffffff
sample_interval: 0 # optional mininum=0 maximum=0xffffffff
stats_block_usecs: 0 # optional mininum=0 maximum=0xffffffff
tx_frames: 0 # optional mininum=0 maximum=0xffffffff
tx_frames_high: 0 # optional mininum=0 maximum=0xffffffff
tx_frames_irq: 0 # optional mininum=0 maximum=0xffffffff
tx_frames_low: 0 # optional mininum=0 maximum=0xffffffff
tx_usecs: 0 # optional mininum=0 maximum=0xffffffff
tx_usecs_high: 0 # optional mininum=0 maximum=0xffffffff
tx_usecs_irq: 0 # optional mininum=0 maximum=0xffffffff
tx_usecs_low: 0 # optional mininum=0 maximum=0xffffffff
ring:
rx: 0 # optional mininum=0 maximum=0xffffffff
rx_jumbo: 0 # optional mininum=0 maximum=0xffffffff
rx_mini: 0 # optional mininum=0 maximum=0xffffffff
tx: 0 # optional mininum=0 maximum=0xffffffff
Configures 802.1x authentication for an interface.
Currently, NetworkManager is the only supported provider and EAP-TLS is the only supported EAP method.
SSL certificates and keys must be deployed on the host prior to running the role.
-
eap
The allowed EAP method to be used when authenticating to the network with 802.1x.
Currently,
tls
is the default and the only accepted value. -
identity
(required)Identity string for EAP authentication methods.
-
private_key
(required)Absolute path to the client's PEM or PKCS#12 encoded private key used for 802.1x authentication.
-
private_key_password
Password to the private key specified in
private_key
. -
private_key_password_flags
List of flags to configure how the private key password is managed.
Multiple flags may be specified.
Valid flags are:
none
agent-owned
not-saved
not-required
See NetworkManager documentation on "Secret flag types" more details (
man 5 nm-settings
). -
client_cert
(required)Absolute path to the client's PEM encoded certificate used for 802.1x authentication.
-
ca_cert
Absolute path to the PEM encoded certificate authority used to verify the EAP server.
-
ca_path
Absolute path to directory containing additional pem encoded ca certificates used to verify the EAP server. Can be used instead of or in addition to ca_cert. Cannot be used if system_ca_certs is enabled.
-
system_ca_certs
If set to
True
, NetworkManager will use the system's trusted ca certificates to verify the EAP server. -
domain_suffix_match
If set, NetworkManager will ensure the domain name of the EAP server certificate matches this string.
The bond
setting configures the options of bonded interfaces
(type bond
). It supports the following options:
-
mode
Bonding mode. See the kernel documentation or your distribution
nmcli
documentation for valid values. NetworkManager defaults tobalance-rr
. -
miimon
Sets the MII link monitoring interval (in milliseconds)
Setting the same connection profile multiple times:
network_connections:
- name: Wired0
type: ethernet
interface_name: eth0
ip:
dhcp4: yes
- name: Wired0
state: up
Activating a preexisting connection profile:
network_connections:
- name: eth0
state: up
Deactivating a preexisting connection profile:
network_connections:
- name: eth0
state: down
Creating a persistent connection profile:
network_connections:
- name: eth0
#persistent_state: present # default
type: ethernet
autoconnect: yes
mac: "00:00:5e:00:53:5d"
ip:
dhcp4: yes
Deleting a connection profile named eth0
(if it exists):
network_connections:
- name: eth0
persistent_state: absent
Configuring the Ethernet link settings:
network_connections:
- name: eth0
type: ethernet
ethernet:
autoneg: no
speed: 1000
duplex: full
Creating a bridge connection:
network_connections:
- name: br0
type: bridge
#interface_name: br0 # defaults to the connection name
Configuring a bridge connection:
network_connections:
- name: internal-br0
interface_name: br0
type: bridge
ip:
dhcp4: no
auto6: no
Setting controller
and port_type
:
network_connections:
- name: br0-bond0
type: bond
interface_name: bond0
controller: internal-br0
port_type: bridge
- name: br0-bond0-eth1
type: ethernet
interface_name: eth1
controller: br0-bond0
port_type: bond
Configuring VLANs:
network_connections:
- name: eth1-profile
autoconnet: no
type: ethernet
interface_name: eth1
ip:
dhcp4: no
auto6: no
- name: eth1.6
autoconnect: no
type: vlan
parent: eth1-profile
vlan:
id: 6
ip:
address:
- 192.0.2.5/24
auto6: no
Configuring MACVLAN:
network_connections:
- name: eth0-profile
type: ethernet
interface_name: eth0
ip:
address:
- 192.168.0.1/24
- name: veth0
type: macvlan
parent: eth0-profile
macvlan:
mode: bridge
promiscuous: yes
tap: no
ip:
address:
- 192.168.1.1/24
Configuring a wireless connection:
network_connections:
- name: wlan0
type: wireless
wireless:
ssid: "My WPA2-PSK Network"
key_mgmt: "wpa-psk"
# recommend vault encrypting the wireless password
# see https://docs.ansible.com/ansible/latest/user_guide/vault.html
password: "p@55w0rD"
Setting the IP configuration:
network_connections:
- name: eth0
type: ethernet
ip:
route_metric4: 100
dhcp4: no
#dhcp4_send_hostname: no
gateway4: 192.0.2.1
dns:
- 192.0.2.2
- 198.51.100.5
dns_search:
- example.com
- subdomain.example.com
dns_options:
- rotate
- timeout:1
route_metric6: -1
auto6: no
gateway6: 2001:db8::1
address:
- 192.0.2.3/24
- 198.51.100.3/26
- 2001:db8::80/7
route:
- network: 198.51.100.128
prefix: 26
gateway: 198.51.100.1
metric: 2
- network: 198.51.100.64
prefix: 26
gateway: 198.51.100.6
metric: 4
route_append_only: no
rule_append_only: yes
Configuring 802.1x:
network_connections:
- name: eth0
type: ethernet
ieee802_1x:
identity: myhost
eap: tls
private_key: /etc/pki/tls/client.key
# recommend vault encrypting the private key password
# see https://docs.ansible.com/ansible/latest/user_guide/vault.html
private_key_password: "p@55w0rD"
client_cert: /etc/pki/tls/client.pem
ca_cert: /etc/pki/tls/cacert.pem
domain_suffix_match: example.com
The network
role rejects invalid configurations. It is recommended to test the role
with --check
first. There is no protection against wrong (but valid) configuration.
Double-check your configuration before applying it.
The network
role supports the same configuration scheme for both providers (nm
and initscripts
). That means, you can use the same playbook with NetworkManager
and initscripts. However, note that not every option is handled exactly the same
by every provider. Do a test run first with --check
.
It is not supported to create a configuration for one provider, and expect another
provider to handle them. For example, creating profiles with the initscripts
provider,
and later enabling NetworkManager is not guaranteed to work automatically. Possibly,
you have to adjust the configuration so that it can be used by another provider.
For example, configuring a RHEL6 host with initscripts and upgrading to RHEL7 while continuing to use initscripts in RHEL7 is an acceptable scenario. What is not guaranteed is to upgrade to RHEL7, disable initscripts and expect NetworkManager to take over the configuration automatically.
Depending on NetworkManager's configuration, connections may be stored as ifcfg files as well, but it is not guaranteed that plain initscripts can handle these ifcfg files after disabling the NetworkManager service.
As Ansible usually works via the network, for example via SSH, there are some limitations to be considered:
The network
role does not support bootstraping networking configuration. One option
may be
ansible-pull.
Another option maybe be to initially auto-configure the host during installation (ISO
based, kickstart, etc.), so that the host is connected to a management LAN or VLAN. It
strongly depends on your environment.
For initscripts
provider, deploying a profile merely means to create the ifcfg
files. Nothing happens automatically until the play issues ifup
or ifdown
via the up
or down
states -- unless there are other
components that rely on the ifcfg files and react on changes.
The initscripts
provider requires the different profiles to be in the right
order when they depend on each other. For example the bonding controller device
needs to be specified before the port devices.
When removing a profile for NetworkManager it also takes the connection
down and possibly removes virtual interfaces. With the initscripts
provider
removing a profile does not change its current runtime state (this is a future
feature for NetworkManager as well).
For NetworkManager, modifying a connection with autoconnect enabled may result in the activation of a new profile on a previously disconnected interface. Also, deleting a NetworkManager connection that is currently active results in removing the interface. Therefore, the order of the steps should be followed, and carefully handling of autoconnect property may be necessary. This should be improved in NetworkManager RFE rh#1401515.
It seems difficult to change networking of the target host in a way that breaks
the current SSH connection of ansible. If you want to do that, ansible-pull might
be a solution. Alternatively, a combination of async
/poll
with changing
the ansible_host
midway of the play.
TODO The current role does not yet support to easily split the play in a pre-configure step, and a second step to activate the new configuration.
In general, to successfully run the play, determine which configuration is active in the first place, and then carefully configure a sequence of steps to change to the new configuration. The actual solution depends strongly on your environment.
When something goes wrong while configuring networking remotely, you might need to get physical access to the machine to recover.
TODO NetworkManager supports a checkpoint/rollback feature. At the beginning of the play we could create a checkpoint and if we lose connectivity due to an error, NetworkManager would automatically rollback after timeout. The limitations is that this would only work with NetworkManager, and it is not clear that rollback will result in a working configuration.
Want to contribute? Take a look at our contributing guidelines!