Hubs
Hubs are a form of repeater for an Ethernet LAN which has multiple ports (they are sometimes also known as "multi-port repeaters" or "active star networks").
Each port of a hub has an RJ-45 connector able to accept a patch cable to connect to a wall outlet. The other end of the cable is normally connected to a network interface card with a 10BT outlet. Many hubs also have an AUI connector which may be used to connect an external transceiver to which other types of Ethernet Media may be attached. (Sometimes a 10B2 connector is also provided to allow connection directly to a coaxial cable thin Ethernet network.) Whatever the type of connector, a single hub is a only able to connect a group of equipments operating at the same speed (i.e. all equipment connected to a 10BT hub must operate at 10 Mbps).
An Ethernet Hub.
Each port (or interface) allows one piece of equipment to be connected to the hub. In this case the system connected via the port F is sending a frame of data to the system connected at port C. The hub is not able to recognise the addresses in the header of a frame,and therefore is unable to identify which port to send to. Therefore, every frame is sent to every output port. (This is in contrast to a bridge, switch or router, each of which only forwards a packet if the destination address of the packet corresponds to a system reachable via the output interface.)
Hubs are a form of repeater for an Ethernet LAN which has multiple ports (they are sometimes also known as "multi-port repeaters" or "active star networks").
Each port of a hub has an RJ-45 connector able to accept a patch cable to connect to a wall outlet. The other end of the cable is normally connected to a network interface card with a 10BT outlet. Many hubs also have an AUI connector which may be used to connect an external transceiver to which other types of Ethernet Media may be attached. (Sometimes a 10B2 connector is also provided to allow connection directly to a coaxial cable thin Ethernet network.) Whatever the type of connector, a single hub is a only able to connect a group of equipments operating at the same speed (i.e. all equipment connected to a 10BT hub must operate at 10 Mbps).
An Ethernet Hub.
Each port (or interface) allows one piece of equipment to be connected to the hub. In this case the system connected via the port F is sending a frame of data to the system connected at port C. The hub is not able to recognise the addresses in the header of a frame,and therefore is unable to identify which port to send to. Therefore, every frame is sent to every output port. (This is in contrast to a bridge, switch or router, each of which only forwards a packet if the destination address of the packet corresponds to a system reachable via the output interface.)
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