Network Devices Explained | Hub, Bridge, Router, Switch

welcome to surprise in this video we're going to be looking at for network devices these are hubs bridges rooters and switches okay first we'll look at the simple hub a hub's job is to connect devices in your network together let's see how it works let's say host a send some data to host see when it had received the data it repeats out of every port except the receiving one who see gets the data but so does host B and D so they simply discharge it the hub has many down force it wastes bandwidth as we seen when host B and D receives unwanted data a hub uses something called half duplex which means it can send and receive data at the same time without causing a data collision this would cause your data to become corrupt and need to be sent again so in overview a hub is a layer one device meaning it has no knowledge of addresses all it does is repeat any data it receives they have one collision domain and uses half duplex this means it can't receive data and receive data at the same time they waste bandwidth by sending data to hosts unnecessarily it has security risks because all the hosts receive everyone's data a malicious user could steal this hubs are old technology they've now been replaced by switches which we will take a look at shortly bridges were introduced to combat some of the shortcomings of hubs they used to segment networks into smaller sections when data reaches the bridge it decides whether or not to Ford the data it does this by looking at the destination and source and MAC address every time the bridge receives data it learns the source address looks at the destination address and decides to send the data or discard the data where we look at this process in more depth when we discuss which is next as it uses a similar process so a bridge is a layer 2 device this means it can understand and learn MAC addresses it segments lands into smaller sections it has two collision domains this means data can be sent or received on each section of the network at the same time a bridge usually has two ports bridges are not used anymore they have also been replaced by switches now let's take a look at switches think of a switch as a hub and bridge rolled into one it connects the devices together but it can also learn which ports connect to which hosts let's see how this works a switch has something called a MAC address table this table will list each MAC address and which port is connected to in this example host a will send some data to host see the switch receives the data but as you can see the MAC address table is empty the switch in this case will Ford the data out of each port just like AB unlike a hub the switch now learns host A's MAC address can be reached on port 1 or when host C sends data back to host a the switch knows exactly where to send the data now if you notice the switch has learnt the host C's MAC address can be found on port 3 using this process very quickly a switch can learn how to reach each host connected to it let's review a switch is a layer 2 device like the bridge it can learn MAC addresses which are known as layer 2 addresses a switch can use full duplex meaning a can send and receive data at the same time this means each port has its own collision domain this is a huge improvement over a hub because it can learn MAC addresses a switch saves huge amounts of bandwidth and now because only the destination host is receiving the data other hosts can't steal it Reuters you can think of Reuters as the doorway out of your internal network and into the outside world to understand what route is due let's take a familiar example let's say this is your home computer this is your switch and this is your router now just on a side note usually a home Rooter has the switch built-in but in an enterprise network there are separate devices so on the other side of the router you have the Internet let's say you send an email or visit a website your computer will send data to the root to using his IP address the root will then forward the traffic out of your home network and into the wonderful world of the Internet when data comes back the Rooter will forward the data back to your computer a Rooter is the way out of your internal network a Rooter uses not only MAC addresses but also IP addresses which means a root sir is a layer 3 device because IP addresses are known as layer 3 addresses it usually has two ports a Rooter is highly configurable and has many many different features that are beyond the scope of this video that's it for basic Network Devices you've learnt about the older hubs and bridges and also the modern standard of switches and rooters I hope you've enjoyed this video if you did don't forget to subscribe leave a comment and give a thumbs up thank you for watching

Channel: CertBros

Views: 295,185

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Keywords: Network Devices Explained, netowrk devices, switches, routers, bridges, hubs, how switches work, how hubs work, how bridges work, bridges explained, switches explained, hubs explained, networking, networking hardware, network

Id: eMamgWllRFY

Length: 6min 12sec (372 seconds)

Published: Thu May 19 2016