Alauda Container Platform

Configure IPv4 Multicast for Kube-OVN Underlay Networks

This guide describes how to enable IPv4 multicast communication for workloads in a Kube-OVN Underlay subnet. After multicast snooping is enabled for a subnet, Kube-OVN configures multicast snooping and a multicast querier on the corresponding OVN logical switch.

This configuration applies to each subnet independently. It does not configure multicast routing between different Layer 3 networks or configure vendor-specific physical switches.

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Before You BeginEnable Multicast SnoopingUsing the Web ConsoleView the Configuration ResultDisable Multicast Snooping

Before You Begin

Make sure the following conditions are met:

  • ACP version: 4.2
  • The target subnet is a Kube-OVN Underlay subnet with spec.protocol set to IPv4. IPv6 and dual-stack subnets are outside the scope of this guide.
  • The physical network has been prepared according to Preparing Kube-OVN Underlay Physical Network.
  • The subnet has at least one available IP address. When multicast snooping is enabled, Kube-OVN creates a multicast querier for the subnet. The querier uses one available IP address from the subnet address pool and an automatically generated MAC address.
  • The physical network permits the multicast group and IGMP traffic used by the application.

If IGMP snooping is enabled on the physical switches, work with the network administrator to verify that multicast membership can be learned on the VLAN ports connected to the cluster nodes and external receivers. The querier and IGMP snooping behavior of physical switches varies by vendor.

Enable Multicast Snooping

Using the Web Console

  1. Go to Administrator.

  2. From the Cluster drop-down list at the top, select the target cluster.

  3. In the left navigation bar, expand Clusters, and then click Resources.

  4. In the resource search box, enter Subnet. Expand Correlated with Cluster, and then select Subnet (kubeovn.io).

  5. Click the action menu (⋮) next to the target Underlay subnet, and then select Update.

  6. Add enableMulticastSnoop: true to spec:

    spec:
  enableMulticastSnoop: true

  7. Click Update.

Repeat these steps for every Underlay subnet that needs to carry multicast traffic.

View the Configuration Result

After the update is complete, view the YAML of the target subnet in the web console and verify the following fields:

  • spec.enableMulticastSnoop is true, indicating that multicast snooping is enabled.
  • status.mcastQuerierIP and status.mcastQuerierMAC have values, indicating that the multicast querier has been created.

If the querier IP or MAC address is empty, make sure the subnet has an available IP address.

Disable Multicast Snooping

In the web console, open the YAML of the target subnet, set spec.enableMulticastSnoop to false, and then click Update.

After the update is complete, Kube-OVN releases the querier IP and MAC address, and status.mcastQuerierIP and status.mcastQuerierMAC become empty.