Multicast provides an efficient way to send data to an interested set of receivers to only one copy of data from the source, by letting the intermediate multicast-routers in the network replicate packets to reach multiple receivers based on a group subscription.
Multicast clients use the Internet Group Management Protocol (IGMP) to propagate membership information from hosts to Multicast enabled routers and PIM to propagate group membership information to Multicast servers via Multicast routers.
Multicast support includes:
- Multicast support on both overlay and underlay
- Protocol-Independent Multicast - Sparse Mode (PIM-SM) on SD-WAN Edge
- Internet Group Management Protocol (IGMP) version 2 on SD-WAN Edge
- Static Rendezvous Point (RP) configuration, where RP is enabled on a 3rd party router.
You can enable and configure Multicast globally and at the interface-level. If required, you can override the Multicast configurations at the Edge-level.
Configure Multicast Globally
To configure Multicast globally:
- Log in to VMware SD-WAN Orchestrator, and then go to Configure > Profiles.
- Either click the Device icon next to the Profile for which you want to configure Multicast Settings, or click the link to the Profile, and then go to the Device tab.
- Scroll down to the Multicast Settings area.
- If the Multicast Settings button is in the Off position, click the Off button to turn On Multicast Settings.
The RP Selection is set to Static by default.
- In the appropriate textboxes for the RP Selection, type in the RP Address and Multicast Group. (See the table below for a description of RP Address and Multicast Group.
- If applicable, select the Enable PIM on Overlay checkbox and enter the IP Source Address.
- Set Advanced Settings, if necessary. Refer to the table that follows for a description of each setting. In the appropriate text boxes, enter PIM Timers for Join Prune Send Interval (default 60 seconds) and Keep Alive Timer (default 60 seconds).
Multicast Settings
The following table describes Multicast settings.
| Multicast Setting | Description |
|---|---|
| RP Selection | Static is the default and supported mechanism. |
| RP Address | Enter the IP address of the device, which is the route processor for a multicast group. |
| Multicast Group | Enter a range of IP addresses and port numbers that define a Multicast group. Once the host device has membership to the Multicast group, it can receive any data packets that are sent to the group defined by the IP address and port number. |
| Enable PIM on Overlay | Enable PIM peering on SD-WAN Overlay. For example when enabled on both branch SD-WAN Edge and hub SD-WAN Edge, they form a PIM peer. By default, the source IP address for the overlays is derived from one of the multicast-enabled underlay interfaces and it is recommended to leave the default. You can choose to change the source IP by specifying Source IP Address, which will be a virtual address and will be advertised over the overlay automatically. |
| PIM Timers | |
| Join Prune Send Interval | The Join Prune Interval Timer. Default value is 60 seconds. |
| Keep Alive Timer | PIM keep alive timer. Default value is 60 seconds. |
Configure Multicast Settings at the Edge-Level
- Log in to VMware SD-WAN Orchestrator, and then go to Configure > Edges.
- Either click the Device icon next to the Edge for which you want to override the Multicast Settings, or click the link to the Edge, and then go to the Device tab.
- Scroll down to the Multicast Settings area, and then select the Enable Edge Override check box.
- If the Multicast Settings button is in the Off position, click the Off button to turn On Multicast Settings, and then configure the required settings. For details, see the Multicast Settings table above.
To configure the multicast settings at the Interface level, see: Configure Interface Settings.
