After a little over 5 months and 245 commits since NetworkManager 1.52, the new release is ready: NetworkManager 1.54.

Let’s take a look at the most interesting parts!

Support for configuring IPv4 forwarding

NetworkManager now supports configuring the per-device IPv4 forwarding sysctl variable net.ipv4.conf.<interface>.forwarding via the “ipv4.forwarding” connection property.

The feature allows users to configure forwarding directly through NetworkManager, enabling targeted forwarding configurations for interfaces.

Loopback configuration in nmtui

It is now possible to configure the loopback interface via nmtui:

WireGuard firewall configuration

When activating a WireGuard connection to an IPv6 endpoint, NetworkManager now creates firewall rules to ensure that the incoming packets are not dropped by kernel reverse path filtering.

Similarly to wg-quick, NetworkManager now creates rules in nft or iptables, depending on availability. When a tunnel is brought up, the generated rules might look something like this:

table ip6 nm-wg-wg1 {
	chain preraw {
		iifname != "wg1" ip6 daddr 2600::1 fib saddr type != local drop
	}

	chain premangle {
		type filter hook prerouting priority mangle; policy accept;
		meta l4proto udp meta mark set ct mark
	}

	chain postmangle {
		type filter hook postrouting priority mangle; policy accept;
		meta l4proto udp meta mark 0x0000cb20 ct mark set meta mark
	}
}

IPv6 prefix delegation

The new version introduces a new prefix-delegation setting which configures how to handle prefix delegation on interfaces.

The prefix-delegation setting includes a subnet-id property that specifies the subnet to choose on the downstream interface when using IPv6 prefix delegation.

NBFT parser in initrd-generator

The nm-initrd-generator utility can now detect and parse a network configuration specified by the NVMe Boot Firmware Table (NBFT) during early boot, and create the necessary connections without additional manual setup.

This allows for more complex configurations, such as booting the system from a remote storage using NVMe over Fabrics.

What else?

• Most of the properties of ovs-bridge and ovs-port connections can now be reapplied at runtime without bringing the connection down.
• Added a new “sriov.preserve-on-down” property that controls whether NetworkManager preserves the SR-IOV parameters set on the device when the connection is deactivated, or whether it resets them to their default value.
• Introduced a new “ovs-dpdk.lsc-interrupt” property to configure the Link State Change (LSC) detection mode for OVS DPDK interfaces.
• Added systemd services to provide networking in the initrd ( NetworkManager-initrd.service, NetworkManager-config-initrd.service, NetworkManager-wait-online-initrd.service).

Acknowledgements

Many thanks to all contributors who provided feedback, ideas or patches.

Antonio Alvarez Feijoo, Beniamino Galvani, Fernando Fernandez Mancera, Filip Pokryvka, Florian Schmaus, Friedrich Altheide, Gris Ge, Herman Semenov, Íñigo Huguet, Jan Tojnar, Jan Vaclav, Kyle Ouellette, Lubomir Rintel, Michael Biebl, NorwayFun, Piotr Drąg, Tomas Bzatek, Tomas Korbar, Vladimír Beneš and Wen Liang.

Also thanks to our Quality Engineers from Red Hat for all the testing: Vladimír Beneš, Filip Pokryvka and Mingyu Shi.

Join us on our GitLab project.

Get the new release

As usual, the next release of your favorite Linux distribution will surely ship the new version.

In case you’re too impatient to wait, or you are, in fact, responsible for keeping NetworkManager up to date in a distribution, get the tarball from our download page.

Thanks for tuning in and goodbye!