What is Art-Net? DMX over Ethernet for beginners

The one-sentence answer

Art-Net is a way to send DMX universes over a normal Ethernet network. Instead of one XLR cable carrying 512 channels, a computer or console sends UDP packets that lighting nodes turn back into DMX. Visualisers, media servers and most Ethernet nodes speak it.

If you already understand DMX start addresses, Art-Net adds one more number: which universe rides in which packet. The fixture still has a start address inside that universe. The node still has a universe (or port) setting that must match the sender.

How a packet becomes light

A sender — a lighting desk, a PC, or a visualiser — builds an ArtDmx packet. The packet names a universe (in Art-Net this is often Net / Sub-Net / Universe) and includes up to 512 channel bytes. A node on the same network listens, and if the universe matches one of its ports, it outputs those bytes as DMX on an XLR.

Discovery exists so devices can find each other. On a small dedicated switch this is convenient. On a shared office network it is how you accidentally light up a printer VLAN or flood a Wi-Fi access point. Treat discovery as a lab feature, not a reason to plug the show PC into venue guest Wi-Fi.

Broadcast, unicast and the show LAN

Art-Net can broadcast: one sender, every device on the subnet hears the packet. That is simple and dangerous. Broadcast plus a large universe count will saturate cheap switches and wireless links. Unicast sends only to the node that needs the universe. Prefer unicast once you know the node IPs.

Put the lighting PC and the nodes on the same subnet, on a wired switch, with a dedicated NIC if the laptop also needs internet. Typical show addressing looks like 2.0.0.x or 10.0.0.x. The exact scheme matters less than “everyone is on one isolated LAN and nobody is routing this onto the POS network.”

UDP port 6454 is the Art-Net port. Operating-system firewalls often block the first show of the night. Allow the lighting app through on that port before you blame the node.

What beginners get wrong

Universe mismatch is the classic. The PC sends universe 0. The node is set to universe 1. The visualiser on the same laptop looks fine because it subscribed to 0. The physical rig stays dark. Always confirm the node’s universe, not only the software output.

Subnet mismatch is next. A PC at 192.168.1.10 cannot talk to a node at 2.0.0.10 without a router, and you do not want a router in this path. Set both to the same prefix and a unique last octet.

Wi-Fi is not a DMX transport. Latency, retries and interference make flicker and dropout. Phones can sit on Wi-Fi for a control surface. The Art-Net stream itself belongs on copper.

Art-Net versus sACN

Both carry DMX over Ethernet. Art-Net is older and extremely common on nodes and visualisers. sACN (E1.31) prefers multicast, which scales more cleanly when many receivers want the same universe. Pick what the hardware already speaks. A festival backbone that insists on sACN is not a reason to rip out Art-Net nodes you already own — use a converter or a sender that can do both.

You do not need to pick a religion on day one. Learn one wired LAN, one universe, one node, one fixture. Then add the second universe. The protocol logo on the packet is the last decision, not the first.

A lab you can run on a desk

Put a node and a laptop on a five-port switch with no uplink. Static IPs, same prefix. Send one universe. Confirm the node’s DMX LED. Plug one fixture at address 1. If that works, add a second node and a second universe before you ever touch a venue backbone.

Then break it on purpose: change the node universe, enable the firewall, pick the Wi-Fi NIC. Watch each failure. The troubleshooting list later in this blog is not theory — it is those three mistakes in order.

When you later plug into a real room, you already know what “no link,” “wrong NIC,” and “universe off by one” look like. That is the difference between a 20-minute fix and rewriting the show file out of panic.

Related

• What is DMX? →
• Art-Net vs sACN →
• Art-Net troubleshooting →