sACN Multicast + IGMP Planner

With queries for “sacn troubleshooting,” “multicast switch settings,” and “network hygiene,” lighting ops teams need a concise planner. Use this checklist before you deploy multiple universes.

Step 1: Inventory universes

• List each sACN universe, fixture count, and bandwidth.
• Document whether each universe must be priority-aware (per-slot priority uses E1.31-1).

Step 2: Choose multicast addressing

• Assign unique multicast IPs (e.g., 239.255.0.0/16) and map them to VLANs.
• Avoid conflicts by reserving increments of 32 universes per subnet.

Step 3: Configure switches

• Enable IGMP Snooping + Querier on every switch.
• Set querier intervals to 50–70 ms, and disable flood on unmanaged switches.
• Use Rate limiting on uplinks if available.

Step 4: Test traffic

• Use a dedicated port to monitor multicast traffic.
• Watch for IGMP joins/leaves, and verify no flooding occurs when universes change.

Field tips

• Document every universe in the DMX Addressing Chart and channel planning guide.
• Mention the DMX Channel Planning Best Practices guide and the DMX Address Capacity Calculator so every universe stays documented.