About this interactive
From the lesson:
- **Unicast:** the switch looks up the destination MAC and forwards the frame out that device's port.
- **Broadcast:** the destination is FF-FF-FF-FF-FF-FF, all 48 bits set to 1. The switch sends it out every port except the one it arrived on. An ARP request is a broadcast. Everything that hears it is the broadcast domain, which ends at the router.
- **Multicast:** one-to-many, to the devices that joined a group. The switch sends it only out the members' ports, once it knows them, by being set up for them or by learning which devices subscribe.
From MAC Address Tables: a unicast frame for a MAC the switch has not learned yet is flooded.
What you'll learn
- Predict how a switch handles a unicast frame (out the destination's one port), a broadcast frame to FF-FF-FF-FF-FF-FF (out every other port) and a multicast frame (out only the ports whose devices joined the group)
- Recognize that a broadcast reaches every device in the Layer 2 broadcast domain and stops at the router
Aligned to
CompTIA Network+
1.4
Explain common networking ports, protocols, services, and traffic types.
Cisco CCNA
1.13
Describe switching concepts
Cisco CCST Networking
4.5
Explain basic switching concepts
Key terms
- Unicast
- A transmission type in which a packet is sent from one source directly to one specific destination device, identified by its unique IP or MAC address. Unicast is the standard delivery method for most internet traffic such as web browsing and file downloads.
- Broadcast
- A transmission type in which one device sends a single packet that is delivered to every other device on the local network segment simultaneously. Broadcast traffic is contained within a broadcast domain and does not cross router boundaries.
- Multicast
- A transmission type in which data is sent from one source to a specific group of devices that have subscribed to a multicast group address, rather than to all devices or just one. This differs from broadcast (all devices) and unicast (one device).
- Broadcast Domain
- A network segment in which a broadcast sent by one device is received by all other devices within that segment; routers define the boundaries of broadcast domains by not forwarding broadcast traffic.
- MAC Address Table
- A table maintained by a switch (also called the CAM table) that maps source MAC addresses to the switch ports on which those devices were learned. When a frame arrives, the switch looks up the destination MAC in this table to forward it out only the correct port rather than flooding all ports.
- Address Resolution Protocol
ARP
- A protocol used to map an IP address to a physical MAC address on a local network.
Topics
Unicast
Broadcast
Multicast
Switch
Broadcast Domain
Mac Address
Interactive
Predict
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