Network CCNA

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Switches

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Hubs vs Switches

before there were switches we used hubs to route network traffic, but: hubs share the packets with all the devices on the hub. the devices that are not expecting the message will just ignore it, but this means if u have access to the hub, you have access to all the traffic between the devices on the hub.

A switch however sends the packet only to the expected device. Wireless access points behave like hubs, it doesn’t matter if the access point is connected to a switch, once a message is sent to the WAP intended for one devices the WAP sends it to all devices connected to it like a hub.

CAM Table(content addressable memory)

a table of mac addresses and ethernet ports on a switch which allows the switch the remember on what port each device is connected to it.

Networking Layers

anything physical is layer 101-Physical Layer, Mac Addresses are layer 2(02-Data Link Layer) and IP addresses are layer 3 (03-Network Layer)

The switch itself is a layer 2 device

messages on layer 2 are called frames, not packets