How to create and configure a network¶
To create and configure a managed network, use the lxc network
command and its subcommands.
Append --help
to any command to see more information about its usage and available flags.
Network types¶
The following network types are available:
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Create a network¶
Use the following command to create a network:
lxc network create <name> --type=<network_type> [configuration_options...]
See Network types for a list of available network types and links to their configuration options.
If you do not specify a --type
argument, the default type of bridge
is used.
Create a network in a cluster¶
If you are running a LXD cluster and want to create a network, you must create the network for each cluster member separately. The reason for this is that the network configuration, for example, the name of the parent network interface, might be different between cluster members.
Therefore, you must first create a pending network on each member with the --target=<cluster_member>
flag and the appropriate configuration for the member.
Make sure to use the same network name for all members.
Then create the network without specifying the --target
flag to actually set it up.
For example, the following series of commands sets up a physical network with the name UPLINK
on three cluster members:
user@host:~$
lxc network create UPLINK --type=physical parent=br0 --target=vm01
Network UPLINK pending on member vm01
user@host:~$
lxc network create UPLINK --type=physical parent=br0 --target=vm02
Network UPLINK pending on member vm02
user@host:~$
lxc network create UPLINK --type=physical parent=br0 --target=vm03
Network UPLINK pending on member vm03
user@host:~$
lxc network create UPLINK --type=physical
Network UPLINK created
Also see How to configure networks for a cluster.
Attach a network to an instance¶
After creating a managed network, you can attach it to an instance as a NIC device.
To do so, use the following command:
lxc network attach <network_name> <instance_name> [<device_name>] [<interface_name>]
The device name and the interface name are optional, but we recommend specifying at least the device name.
If not specified, LXD uses the network name as the device name, which might be confusing and cause problems.
For example, LXD images perform IP auto-configuration on the eth0
interface, which does not work if the interface is called differently.
For example, to attach the network my-network
to the instance my-instance
as eth0
device, enter the following command:
lxc network attach my-network my-instance eth0
Attach the network as a device¶
The lxc network attach
command is a shortcut for adding a NIC device to an instance.
Alternatively, you can add a NIC device based on the network configuration in the usual way:
lxc config device add <instance_name> <device_name> nic network=<network_name>
When using this way, you can add further configuration to the command to override the default settings for the network if needed. See NIC device for all available device options.
Configure a network¶
To configure an existing network, use either the lxc network set
and lxc network unset
commands (to configure single settings) or the lxc network edit
command (to edit the full configuration).
To configure settings for specific cluster members, add the --target
flag.
For example, the following command configures a DNS server for a physical network:
lxc network set UPLINK dns.nameservers=8.8.8.8
The available configuration options differ depending on the network type. See Network types for links to the configuration options for each network type.
There are separate commands to configure advanced networking features. See the following documentation: