HUB
Last updated
Last updated
When the first 10BASE-T (Twisted Pair Cable) connection was introduced in 1990 providing the first 10Mbps connection, HUB was the first device used with a HALF Duplex logic before the other were invented.
HUB is an L1 device because it uses Physical Layer Standards rather than Data-Link Layer Standards.
When received a frame on its port, HUB just like a Dumb Repeater copy & forward (repeat) it to all the other ports except the incoming port. Hence it is also called a Multi-Port Repeater.
HUB is a Half-Duplex device as it does not have any mechanism of Collision Detection/Avoidance, Hence if 2 Frames are sent at a time to a HUB (usually the case in FULL-Duplex devices) the Frame just collides.
Hence to the neighbor device connected to a HUB must always set it's Duplex settings to Half-Duplex.
CCNA 200-301 OCG, Volume 1, Pg. 55 - Wendell Odom.