When the clock status tab in Dante Controller shows more than one leader clock, it can possibly be a problem with IGMP snooping.
- Multiple devices appear as the Primary Leader Clock in Dante Controller.
- Devices do not appear or information is missing in Dante Controller.
- High levels of network traffic or bandwidth utilization on all devices.
- Computers using Dante Virtual Soundcard listed as ‘Listening’
If you are not experiencing any of these issues, you likely do not need to worry about IGMP snooping. If you are experiencing one or more of these issues, then there are two possible solutions: disable IGMP Snooping and Multicast filtering, or configure IGMP Snooping on the switch correctly.
When to Disable IGMP Snooping
Small, isolated networks with a single switch that have only Dante-enabled devices generally do not require IGMP snooping, as the amount of Multicast generated will be very low (Multicast traffic is used only for clocking, discovery, and control in these cases—not audio). In these cases, disable all Multicast filtering or use an unmanaged, gigabit switch that does not support EEE (ensure it is not listed under Disqualified Network Switches). We recommend IGMP snooping in any network with more than 80Mbps of multicast traffic. This is total, not the same number as listed at the bottom of Dante Controller. That number only indicates the amount of Dante Multicast Audio traffic. If any device in the network status Rx Bandwidth column shows the amount of traffic in yellow or red, IGMP snooping is going to be required.
When to Configure IGMP Snooping
IGMP Snooping is required when:
- Multicast Dante or AES67 flows are in use.
- Dante traffic is mixed with other Multicast traffic, such as Multicast video systems.
- Critical control systems are on the same network as Dante devices, such as Crestron/AMX/Extron control devices.
- Using Dante in 100M (Fast Ethernet) networks, as bandwidth is limited (we do not recommend using 100Mbps switches).
- Using a Wi-Fi access point on the same network as Dante devices (Dante multicast data can flood the Wi-Fi, and therefore we generally do not recommend using Wi-Fi access points on Dante networks).
IGMP Snooping helps prevent transmission of Multicast traffic to ports that don’t need them. On larger, shared networks with Dante or AES67 multicast flows, IGMP Snooping greatly reduces the amount of Multicast traffic on the network by only forwarding Multicast data to the devices that request it. For more in depth training on network configuration, the level 3 Dante Certification course is recommended: https://www.audinate.com/learning/training-certification/dante-certification-program
How to Configure IGMP Snooping
You should only attempt to configure IGMP Snooping on isolated AV networks. For Enterprise networks, please consult with the network management team for the location.
In some rare cases, you may need to add IGMP static routes to each Dante-enabled device port on the VLAN. Only add these if your switch does not work after configuring it according to our switch configuration guide, or when there are high bandwidth Multicast devices such as IP Video. Static filters ensure that the PTP, mDNS, Discovery, and audio traffic is always available throughout the VLAN. IGMP static routes may be required for:
- PTP traffic: 224.0.1.129-132
- Dante Control: 224.0.0.230, 224.0.0.231, 224.0.0.232, and 224.0.0.233
- The specific Dante or AES67 Multicast audio addresses in use.
The rest of the Dante ports and addresses in use are located here: https://www.audinate.com/learning/faqs/which-network-ports-does-dante-use
Additional Tips
- Ensure that Filter Unregistered Multicast is not enabled. Some switches ship with this feature enabled. This blocks traffic that should be allowed (mDNS, PTP, Dante Discovery) and usually results in devices failing to appear in Dante Controller.
- If you’re hearing audio distortion, artifacts, pops and/or clicks, that is usually a problem with software on a computer. If the computer is still listed as listening after configuring IGMP snooping, contact Audinate support: https://www.audinate.com/contact/support
- Fast Leave will not harm a Dante network and is generally required for Multicast video traffic.
- Only one IGMP querier can be configured in a network as a general rule. The IGMP query interval should be 30 for a Dante network.
- IGMP proxies are not supported by Audinate.
- PIM routing is not supported.