Hub • Connects multiple workstations, servers, and other devices to a network. • Can be used to connect two or more computers to one network port. • Handles data types called ‘frames’ • Frames handle network data • A hub sends every frame it receives onto each port • It does not have any way to tell which port a frame is meant for . • Think of it as a shotgun approach, rather than targeting a port it shoots them out of all of them. • It puts lots of excess traffic on the network. • Shares bandwidth among its ports, so that if more than one pc is connected bandwidth is decreased and the connection is slower overall. • Consumer grade hubs cost about $10-$50
Hub Diagram This diagram shows a hub in action. It receives frames from the server then forwards them onto the connected workstations.
Switch • Connects multiple workstations, servers, and other devices to a network. • Can be used to connect two or more computers to one network port. • Like hubs, switches handle Frames • Unlike the ‘shotgun approach’ of a hub, a switch sends frames only to the correct ports. • This is done using MAC addresses. Each frame contains the mac address its going to, and the switch sends it on to the correct mac address • This puts less traffic on the network than a hub • Allocates 10/100 Mbps to each port, so the bandwidth is not shared between ports. • Consumer grade switches cost about $10-$50
Switch Diagram A switch works very similarly to a hub, the only difference is that it is more efficient. Thus the diagram is the same as the diagram for the hub.
Router • A router routes packets to their destination, hence the name ‘router’ • Typically used to connect two networks together – such as a home’s LAN(Local Area Network) to an ISP(Internet Service Provider)’s WAN(Wide Area Network) • Uses headers and forwarding packets to send packets to their destination • Most Current Router’s have many features built in: • DHCP server – sets up ip addresses for devices connected to it • Switch – sends traffic to the right ports • Firewall – blocks ports from receiving unsolicited/unwanted traffic at a hardware level and allows users to open ports they need • Wireless Access Point – lets wireless devices connect to the networks the router is on • Consumer Routers tend to run from $30-$150 depending on the features they offer
Router diagram • In this diagram, the router is connecting a home network with a computer and a Nintendo Wii to the WAN of an internet service provider.
Bridges • A bridge ‘bridges’ the gap between local networks or segments of the same network. • One example of a bridge is to go between different types of connections – for example to go from electrical wiring to Ethernet if running new cable isn’t possible • Uses MAC addresses for switching • Powerline bridges cost about $75
Bridge diagram This diagram shows a Powerline bridge bridging the gap between Ethernet and a home’s electrical system.
Firewall • A firewall blocks access to a network by closing off network ports. Its named after the firewall that cars have between the dash and the engine that protects occupants from fire. • Firewalls are typically configured by blocking all network ports except ones configured to be open by a network operator. This is called white-listing • Most routers today have firewalls built in, if you have ever had to open a port for file-sharing or video games then you’ve encountered a firewall. • Firewalls protect networks from malicious traffic, denial of service attacks, and script kiddies who try to get into a network in various nefarious ways • Firewalls in an enterprise setup can cost thousands of dollars, but for consumers routers with built in firewalls cost $50-$150.
Firewall diagram • Here you can see a firewall placed just after an internet connection blocking traffic.
Gateway • A gateway is the term used for a device that connects one network to another network. • Typically used to connect to an ISP(Internet Service Provider), cable/dsl modems are an example • Like a router, it uses headers and forwarding packets to send packets to their destination • Consumer Gateways tend to run from $75-$150 depending on the features they offer
Gateway diagram • In this diagram, the gateway connects to the ISP and the client connects to the gateway.
Wireless ap • A wireless access point provides wireless access to computer s on a network through Wi-Fi • Typically used in homes as an alternative to running Ethernet cable • Uses headers and forwarding packets to send packets to their destination, similar to a router • Consumer Aps tend to run from $30-$150 depending on the features they offer
Wireless ap diagram • This is a diagram of an entirely wireless network that uses an access point. This access point connects wirelessly to two bridges that connect to devices that only have an Ethernet port as well as wirelessly connecting to laptops.
This is a diagram of all the devices shown in the slide show together. A cable modem connects the network to the internet A firewall blocks bad connections before going to the router The router acts as a Wireless AP and routes traffic to the rest of the network The router connects to a bridge that’s connected to the electrical wiring Another bridge connects to a switch that connects two clients The bridges may be useful, for example, if the wireless does not reach an office on the other side of a house.