Is multicast Layer 2 or Layer 3?

In most cases, multicast packets must pass through Layer 2 switching devices between multicast receivers and Layer 3 multicast routers. After a router forwards multicast packets to a switch, the switch forwards the multicast packets to multicast receivers.

Does multicast work in a Layer 2?

Layer-2 multicast traffic is typically transported in the overlay. In the VXLAN BGP EVPN fabric, Layer-2 multicast refers to the use of IP multicast technology for transporting multicast traffic in a Layer-2 switching environment.

Does IGMP use Layer 2?

IGMP is a layer 3 protocol, which means that switches (operating at layer 2) should be unaware of it.

Can multicast be routed?

Much like broadcast, there are special addresses designated for multicast data. The difference is that some of these can be routed, and used on the Internet. The multicast space reserved by IANA is 224.0.

What is Layer 3 multicast?

A multicast routing protocol runs on Layer 3 multicast devices to establish and maintain multicast routes and correctly and efficiently forward multicast packets. Multicast routes constitute loop-free data transmission paths (also known as multicast distribution trees) from a data source to multiple receivers.

How is multicasting done at network layer?

Network-assisted multicast may also be implemented at the Internet layer using IP multicast. In IP multicast the implementation of the multicast concept occurs at the IP routing level, where routers create optimal distribution paths for datagrams sent to a multicast destination address.

Do you need IGMP in multicast?

IGMP is an integral part of IP and must be enabled on all routing devices and hosts that need to receive IP multicast traffic.

Does multicast work across subnets?

Yes you can have multiple casters (actors) on a subnet using the same multicast address. Sometimes this is how actors find their neighbors. The receiving party can not respond to the sending party directly (using a unicast message) but they can reply by sending their own multicast message.

Should I enable multicast routing?

The benefit of higher multicast rate is to lower the amount of wireless collisions that your wifi data may have. The biggest effect is seen only when you run multiple media streaming devices or services at the same time. First off, the best setting for multicast rate for your router is usually the lowest amount.

What network layer is Multicast?

link layer
Multicast addressing can be used in the link layer (layer 2 in the OSI model), such as Ethernet multicast, and at the internet layer (layer 3 for OSI) for Internet Protocol Version 4 (IPv4) or Version 6 (IPv6) multicast.