Network Components By Kagan Strayer

Network Components This presentation will cover various network components and their functions. The components that will be covered are: Network hubs Network switches Network routers Network bridges Network gateway Network firewall Network wireless access point

Network Hub Using a network hub is one of the most basic ways to set up a network. Hubs function on layer 1 of the networking protocol. When a packet is sent to a hub it is propagated to all devices connected to the hub at the same time. Only one packet can be sent through the hub at a time. When a message is broadcasted the hub sends it to every device on its network General costs are between $10-$40 based on how many ports and features. Some hubs may cost more because they have more features than a basic hub.

Network Hub Cont. A Hub can be connected to other networks/the internet(2) via the Link/Out port. Some hubs let you configure it any way you want. A hub can be used when a very simple LAN is all that is needed. The relatively low cost can also be factored into when and where to use a hub. However, when it comes to network security it should be limited in use or at least highly monitored due to the fact that all information in the network is shared to all devices connected to it.

Network Hub Cont. A hub does not know what computers are on its network nor does it know where they are in the network. Communication across the network is Asynchronous.

Network Switch Network switches work similarly to that of Hubs but are a little more complex and expensive. Network switches operate on the second layer of the networking protocol. This means that packets are sent with the sender and receiver’s MAC addresses attached to them along with other information. When first initialized, the switch has a blank switch table. The first time a computer sends a message to the switch it records the computer’s MAC address and it’s location. It then stores this information into its switch table. Because it functions on layer 2 it only sends the message to the receiving computer and no one else. However, if a user broadcasts a message the switch sends it to all devices on its network minus the original sender.

Network Switch Cont. Network switches support full-duplex communication. This means that packets can be sent and received across the switch at the same time. There is also no limit to how many packets can be sent at a time. A switch can also be connected to other networks/the internet just like a hub. A switch can be used in a network that might be a lot more complex or has a lot of devices on the network. A switch can also be used where data transmission speed and security is a priority. Companies and schools tend to use switches when they simply want to expand the network without creating another link to the internet.

Network Switch Cont. Network switches cost around $20-$100 based on what features they have. Some switches can cost considerably more if they come with features not normally found on switches like built in firewalls.

Network Switch Cont. Although a switch network shares a lot of similarities to a hub network it is important to remember that a switch network supports full- duplex communication and does not propagate every message to all users on the network. This means that if PC1 wants to talk to PC8,PC7 will never know.

Network Router A router is used to connect one network with another one. It is generally used to connect a LAN to the internet or a WAN. Switches are then used to propagate the network throughout the complex. Routers work on the third layer of the protocol using IP addresses to communicate between networks. Like a switch a router has a routing table that it uses to send packets to other networks. When a router receives a packet from a user on its network it removes the L2 information from the packet finds a route to send the message and attaches its MAC address as the sender address and the destination device’s MAC address as the receiver.

Network Router Cont. Routers cost around $20 for the very basic hardwire/wireless router to $2,000 for more complex routers. Routers never forward broadcasts that it receives. A network on a router is an independent network.

Network Router Cont. A router does not always need a modem to connect to the internet or other WANs. A modem is needed when the incoming data line differs from what the router uses i.e. a phone line into a CAT or optical network.

Network Bridge A network bridge acts similarly to that of a router. One main difference between a router and a bridge is the fact that all of the devices that are connected to the bridge becomes a part of the primary network. This means that a bridge does not operate its own network, instead it facilitates a connection. It does however make its own forwarding decisions. A network bridge is used when you want to connect remote devices to the main network. This is beneficial when the devices are a good distance away from the main network. A network bridge can be hardwired, wireless, or both and operates on the second layer of the protocol.

Network Bridge Cont. Some routers and wireless routers come with a built in bridge setting to where they can act as a bridge. There are however dedicated hardware for creating bridges. Bridges have similar costs as routers ranging from $20-$2,000 depending on the features.

Network Bridge Cont. The fact that some routers have a bridge mode or setting means that you can repurpose a router to work as a bridge. If you do not own any spare routers that can be converted to bridges then it can be more cost effective to buy a bridge.

Network Gateway In this presentation a gateway is a piece of hardware that connects two networks that utilize different layers of the protocol. This is helpful when a location has multiple networks that utilize different layers of protocol. Due to the fact that gateways operate on multiple layers of the protocol and may posses other security features they have a rather large range in cost from $20 to $5,000.

Network Gateway Cont. Just like a bridge several other components of a network can act as a gateway. However, there are times when you need a dedicated gateway for security reasons.

Network Firewall A network firewall is designed to monitor the packets going into and out of the network. It has a filtering table that it uses to check the communication across the network for any flagged packets. Firewalls can also be configured to limit what users on the network can access outside the network. A firewall is usually positioned between the router and the rest of the devices on the network. Some other network devices like routers and gateways come with built in firewall capabilities. However, in some cases depending on what information is on the network it may be necessary to have a dedicated firewall hardware device.

Network Firewall Cont. Firewall hardware also come with wireless support. Firewalls range in cost from $20 all the way up to almost $80,000 based on what features and support they provide.

Network Firewall Cont. Firewalls are a critical part of a secure network. If a firewall is not installed or properly configured it can put everything on the network at risk.

Network Wireless AP A wireless access point (WAP) is a network device that allows other devices connect to the network via a wireless signal. WAPs utilize the wireless signal standard. There are various forms of each with varying speeds. A WAP is used in a network when an unknown number of users will be connecting to the network. It is also used when most of the users will utilize a wireless connections to reach the network. WAPs cost vary from $20 to $10,000 based on what features they have, what form of they support, and their range.

Network Wireless AP Cont. Many devices on the network can have the capability to act as a WAP. It may be important to have a dedicated WAP on a network in order to control what devices can connect to the internet and what they have access to.

Network Wireless AP Continued WAP is a great way to allow users to connect to your network without having to expand the infrastructure.

Network Diagram