Configuring a multicast-mode VXLAN
A multicast-mode VXLAN supports the following multicast methods:
PIM—VTEPs and transport network devices run PIM to generate multicast forwarding entries. On a VTEP, you can use the IP address of a loopback interface as the source IP address for multicast VXLAN packets. If the VTEP has multiple transport-facing interfaces, PIM dynamically selects the outgoing interfaces for multicast VXLAN packets.
IGMP host—VTEPs and transport network devices run PIM and IGMP to generate multicast forwarding entries.
Transport-facing interfaces of VTEPs act as IGMP hosts.
Transport network devices connected to a VTEP run IGMP.
All transport network devices run PIM.
On a VTEP, you must use the IP address of the transport-facing interface as the source IP address for multicast VXLAN packets. If the VTEP has multiple transport-facing interfaces, multicast VXLAN packets are sent to the transport network through the interface that provides the source IP address for multicast VXLAN packets.
VTEPs in a multicast-mode VXLAN can use different multicast methods.
For a multicast-mode VXLAN to flood traffic, you must perform the following tasks in addition to multicast-mode configuration:
Enable IP multicast routing on all VTEPs and transport network devices.
Configure a multicast routing protocol on transport network devices. A VTEP can be both a multicast source and multicast group member. As a best practice, use BIDIR-PIM.
Enable IGMP on transport network devices that are connected to an IGMP host-enabled VTEP.