Chapter 26. Using nmstate-autoconf to automatically configure the network state using LLDP
Network devices can use the Link Layer Discovery Protocol (LLDP) to advertise their identity, capabilities, and neighbors in a LAN. The
nmstate-autoconf utility can use this information to automatically configure local network interfaces.
nmstate-autoconf utility is provided as a Technology Preview only. Technology Preview features are not supported with Red Hat production Service Level Agreements (SLAs), might not be functionally complete, and Red Hat does not recommend using them for production. These previews provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
See Technology Preview Features Support Scope on the Red Hat Customer Portal for information about the support scope for Technology Preview features.
26.1. Using nmstate-autoconf to automatically configure network interfaces
nmstate-autoconf utility uses LLDP to identify the VLAN settings of interfaces connected to a switch to configure local devices.
This procedure assumes the following scenario and that the switch broadcasts the VLAN settings using LLDP:
enp2s0interfaces of the RHEL server are connected to switch ports that are configured with VLAN ID
100and VLAN name
enp3s0interface of the RHEL server is connected to a switch port that is configured with VLAN ID
200and VLAN name
nmstate-autoconf utility then uses this information to create the following interfaces on the server:
bond100- A bond interface with
prod-net- A VLAN interface on top of
bond100with VLAN ID
mgmt-net- A VLAN interface on top of
enp3s0with VLAN ID
If you connect multiple network interfaces to different switch ports for which LLDP broadcasts the same VLAN ID,
nmstate-autoconf creates a bond with these interfaces and, additionally, configures the common VLAN ID on top of it.
nmstatepackage is installed.
- LLDP is enabled on the network switch.
- The Ethernet interfaces are up.
Enable LLDP on the Ethernet interfaces:
Create a YAML file, for example
~/enable-lldp.yml, with the following contents:
interfaces: - name: enp1s0 type: ethernet lldp: enabled: true - name: enp2s0 type: ethernet lldp: enabled: true - name: enp3s0 type: ethernet lldp: enabled: true
Apply the settings to the system:
# nmstatectl apply ~/enable-lldp.yml
Configure the network interfaces using LLDP:
Optional, start a dry-run to display and verify the YAML configuration that
# nmstate-autoconf -d enp1s0,enp2s0,enp3s0 --- interfaces: - name: prod-net type: vlan state: up vlan: base-iface: bond100 id: 100 - name: mgmt-net type: vlan state: up vlan: base-iface: enp3s0 id: 200 - name: bond100 type: bond state: up link-aggregation: mode: balance-rr port: - enp1s0 - enp2s0
nmstate-autoconfto generate the configuration based on information received from LLDP, and apply the settings to the system:
# nmstate-autoconf enp1s0,enp2s0,enp3s0
If there is no DHCP server in your network that provides the IP settings to the interfaces, configure them manual. For details, see:
Display the settings of the individual interfaces:
# nmstatectl show <interface_name>