What Happens on the Switch Port?

About this interactive

From the lesson: - **Hub:** sends every frame out every other port, so everyone can listen in, only one device can talk at a time (half duplex) and two at once collide. - **Switch:** sends a frame out only the port its destination is on. Each port is its own collision domain, so devices talk at the same time, in full duplex. - **Duplex setting:** a port can run full or half duplex. A hub on the other end can only do half duplex, so that link runs half duplex. - **Speed setting:** usually both ends autonegotiate the best speed and duplex they share, and you need not touch it. An old device that cannot autonegotiate, fixed at one speed and duplex, needs the switch port set by hand to match, or errors pile up. - The video says most switches default to full duplex. Strictly, ports default to auto, and with modern devices auto settles on full duplex.

What you'll learn

Predict how a switch handles traffic compared with a hub: a frame sent only to its destination's port, one collision domain per port, and full duplex
Predict what speed and duplex a switch port runs at, and decide when autonegotiation is enough and when the port must be set by hand

Aligned to

CompTIA Network+

2.2 Given a scenario, configure switching technologies and features.

Cisco CCNA

1.4 Identify interface and cable issues

1.13 Describe switching concepts

Key terms

Switch: A network device that connects devices within a LAN and forwards traffic based on MAC addresses.
Autonegotiation: A mechanism that allows network devices to automatically negotiate a common speed and duplex setting without manual configuration.
Half Duplex: A communication mode that allows data to be transmitted in both directions but only one direction at a time.
Full Duplex: A communication mode that allows data to be transmitted in both directions simultaneously.
Collision Domain: A network segment where data packets can collide with each other when transmitted simultaneously.
Hub: A basic Layer 1 network device that receives a signal on one port and repeats it out every other port simultaneously, creating a single shared collision domain among all connected devices. Hubs have been replaced by switches in modern networks because they waste bandwidth and cause collisions.

Topics

Switch Hub Duplex Speed Autonegotiation Collision Domain Interactive Predict

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