The Basics of Computer Networks: Network Devices

This is a multi-part series on DevOps 101. Access the complete DevOps series by clicking HERE

Access the OSI and TCP/IP Models (Previous post in Networking) by clicking HERE

Access the The Basics of Computer Networks: DNS and IP Address (Next post in Networking) by clicking HERE

Network devices are the physical components that make up a computer network. They are responsible for sending, receiving, and routing data between devices on the network. There are many different types of network devices, each with its own specific purpose like the following:

• Hub
• Repeater
• Bridge
• Switch
• Router
• Gateway
• Modem
• Access Point

Now, let’s look at each one of them in detail

Hub

A hub is a simple network device that amplifies and repeats electrical signals from one port to all other ports. Hubs are not intelligent devices, and they do not filter or sort traffic. This means that all data sent to a hub is broadcast to all other devices connected to the hub. This can lead to congestion and performance problems on busy networks.

When a hub receives a data signal from one port, it amplifies the signal and repeats it to all other ports. This means that all devices connected to the hub can see all data that is sent to any device on the hub.

Hubs are very inexpensive and easy to install. They are also a good choice for small networks that do not need a lot of performance or security.

Hubs are a good choice for small networks that do not need a lot of performance or security. They are also a good choice for networks where you need to connect a large number of devices.

There are two main types of network hubs: active hubs and passive hubs.

• Active hubs have a built-in processor that helps to improve performance. They do this by caching data and forwarding it to the correct destination port more quickly.
• Passive hubs do not have a built-in processor. They simply repeat all data that is sent to any of their ports to all of the other ports.

As mentioned above, there are two main types of network hubs: active and passive. Active hubs have a built-in processor that helps to improve performance. Passive hubs do not have a built-in processor and are therefore less expensive.

Active hubs are generally the better option for businesses and other organizations that need to improve network performance. Passive hubs are a good option for home users or small businesses that do not need the extra performance boost.

There are several advantages to using a network hub.

• Easy to set up. Network hubs are very easy to set up. Simply connect each device to the hub using an Ethernet cable and you are ready to go.
• Inexpensive. Network hubs are relatively inexpensive. This makes them a good option for small businesses or home users on a budget.
• Scalable. Network hubs can be easily scaled to accommodate more devices. Simply add additional hubs as needed.

There are also a few disadvantages to using a network hub.

• Performance. Network hubs can have a negative impact on network performance. This is because all data that is sent to any of the hub’s ports is repeated to all of the other ports. This can lead to congestion and decreased throughput.
• Security. Network hubs do not provide any security features. This means that all data that is sent on the network can be seen by all devices that are connected to the hub.

Repeater

A repeater is a device that amplifies or regenerates an electronic signal to extend its reach. Repeaters are used in a variety of networking applications, including wired and wireless networks.

In wired networks, repeaters are used to extend the length of a network cable. When a signal travels over a long cable, it can weaken and become distorted. A repeater amplifies the signal, restoring it to its original strength. This allows the signal to travel over a longer distance without being corrupted.

In wireless networks, repeaters are used to extend the range of a wireless network. When a wireless signal travels over a long distance, it can weaken and become too weak to be received by a device. A repeater amplifies the signal, restoring it to its original strength. This allows the signal to travel over a longer distance and be received by devices that are further away from the wireless access point.

Repeaters are an important part of many networking applications. They allow networks to be extended to longer distances and provide better coverage for devices.

There are two main types of repeaters: passive and active.

• Passive repeaters simply amplify the signal that they receive. They do not perform any other processing on the signal.
• Active repeaters amplify the signal and also perform some processing on the signal. This processing can include error correction, noise filtering, and frequency translation.

Repeaters offer a number of advantages, including:

• Increased range: Repeaters can be used to extend the range of a network. This can be useful for businesses or homes that have a large area to cover.
• Improved performance: Repeaters can improve the performance of a network by reducing signal attenuation and noise. This can lead to faster data transfers and better overall performance.
• Reduced cost: Repeaters can be a more cost-effective solution than installing new cables or expanding the network infrastructure.

Repeaters also have some disadvantages, including:

• Performance degradation: Repeaters can introduce some performance degradation, as they must amplify the signal. This can lead to slower data transfers and higher latency.
• Complexity: Repeaters can add complexity to a network, as they must be configured and managed.
• Security risks: Repeaters can introduce security risks, as they can be used to eavesdrop on network traffic.

Bridge

A bridge is a network device that connects multiple network segments. Bridges work at the data link layer of the OSI model and use MAC addresses to forward frames between segments.

Bridges are transparent to hosts, which means that hosts on different segments do not need to be aware of the bridge’s existence. Bridges learn the MAC addresses of devices on each segment and use this information to forward frames.

Bridges can be used to improve performance, reliability, and security of a network. Bridges can improve performance by reducing the amount of traffic that needs to be sent to the router. Bridges can improve reliability by isolating problems to a single segment. Bridges can improve security by preventing unauthorized access to a network segment.

There are two main types of bridges:

• Transparent bridges: Transparent bridges are the most common type of bridge. They learn the MAC addresses of devices on each segment and use this information to forward frames.
• Learning bridges: Learning bridges are a type of bridge that uses a learning algorithm to learn the MAC addresses of devices on each segment. Learning bridges are more efficient than transparent bridges, but they are also more complex.

Bridges can be used in a variety of networking applications, including:

• Extending a network: Bridges can be used to extend a network by connecting multiple network segments.
• Segmenting a network: Bridges can be used to segment a network by dividing it into smaller, more manageable segments.
• Isolating traffic: Bridges can be used to isolate traffic between different segments.
• Improving performance: Bridges can improve performance by reducing the amount of traffic that needs to be sent to the router.
• Improving reliability: Bridges can improve reliability by isolating problems to a single segment.
• Improving security: Bridges can improve security by preventing unauthorized access to a network segment.

Bridges are an important part of many networking applications. They allow networks to be extended, segmented, and secured. Bridges can also improve performance and reliability of a network.

Here are some additional benefits of using bridges in networking:

• Cost savings: Bridges can be a more cost-effective solution than installing new cables or expanding the network infrastructure.
• Ease of use: Bridges are easy to configure and manage.
• Scalability: Bridges can be scaled to meet the needs of a growing network.

A bridge is a network device that connects two or more network segments. Bridges are intelligent devices, and they can filter and sort traffic. This allows bridges to create separate broadcast domains, which can improve performance and security.

Switch

A network switch is a device that connects multiple devices together on a local area network (LAN). Switches are responsible for forwarding data packets between devices on the network. They do this by maintaining a table of MAC addresses, which is a unique identifier for each device on the network. When a switch receives a data packet, it looks up the destination MAC address in its table and forwards the packet to the port that the device is connected to.

There are three main types of switches:

• Managed switches: Managed switches are more complex than unmanaged switches and offer a wider range of features. Managed switches can be configured to provide a variety of network services, such as quality of service (QoS), port security, and virtual LANs (VLANs).
• Unmanaged switches: Unmanaged switches are simpler and less expensive than managed switches. Unmanaged switches do not offer any configuration options and can only be used to connect devices to a network.
• Layer 2 switches: Layer 2 switches are the most common type of switch. They operate at the second layer of the OSI model, which is the data link layer. Layer 2 switches provide a number of features, such as frame forwarding, address learning, and collision detection.
• Layer 3 switches: Layer 3 switches are more complex than layer 2 switches and operate at the third layer of the OSI model, which is the network layer. Layer 3 switches can route data between different networks.
• PoE switches: PoE switches provide power over Ethernet (PoE) functionality. PoE allows network devices, such as wireless access points and IP phones, to be powered by the network cable.

There are three main types of switches:

• Managed switches: Managed switches are more complex than unmanaged switches and offer a wider range of features. Managed switches can be configured to provide a variety of network services, such as quality of service (QoS), port security, and virtual LANs (VLANs).
• Unmanaged switches: Unmanaged switches are simpler and less expensive than managed switches. Unmanaged switches do not offer any configuration options and can only be used to connect devices to a network.
• Layer 2 switches: Layer 2 switches are the most common type of switch. They operate at the second layer of the OSI model, which is the data link layer. Layer 2 switches provide a number of features, such as frame forwarding, address learning, and collision detection.
• Layer 3 switches: Layer 3 switches are more complex than layer 2 switches and operate at the third layer of the OSI model, which is the network layer. Layer 3 switches can route data between different networks.
• PoE switches: PoE switches provide power over Ethernet (PoE) functionality. PoE allows network devices, such as wireless access points and IP phones, to be powered by the network cable.

Router

A router is a network device that connects two or more networks. Routers are responsible for routing data between networks. They do this by using routing tables, which store the addresses of all the networks that the router knows about. Routers also use routing protocols, which are algorithms that routers use to exchange routing information with each other.

When a router receives a data packet, it looks at the destination IP address of the packet. The router then consults its routing table to find the best path to the destination network. Once the router has found the best path, it forwards the packet to the next router on the path.

There are two main types of routers:

• Home routers: Home routers are designed for home networks. They typically have a few ports for wired connections and a built-in wireless access point.
• Enterprise routers: Enterprise routers are designed for large businesses and organizations. They have more ports and features than home routers.

Routers offer a number of advantages, including:

• Connectivity: Routers allow multiple networks to communicate with each other. This can be helpful for businesses that have multiple locations or for homes that have multiple devices that need to be connected to the internet.
• Security: Routers can help to protect networks from unauthorized access. They can do this by using firewalls and other security features.
• Performance: Routers can improve the performance of networks by routing data packets more efficiently.

Routers also have a few disadvantages, including:

• Cost: Routers can be expensive, especially enterprise routers.
• Complexity: Routers can be complex to set up and configure.
• Security: Routers can be a target for hackers. It is important to keep routers up to date with the latest security patches.

Gateway

A gateway is a device that connects two or more networks that use different protocols. It is a network node that acts as an entry point to another network. Gateways are used to translate between different network protocols, such as IP and Ethernet. They can also be used to provide security and routing services.

There are two main types of gateways: hardware and software. Hardware gateways are physical devices that contain the necessary hardware and software to connect and translate between different networks. Software gateways are software applications that run on a server or computer.

Gateways perform a variety of functions, including:

• Protocol translation: Gateways translate between different network protocols, such as IP and Ethernet. This allows devices on different networks to communicate with each other.
• Security: Gateways can be used to provide security for a network. They can do this by filtering traffic, blocking unauthorized access, and enforcing security policies.
• Routing: Gateways can be used to route traffic between different networks. This allows devices on different networks to communicate with each other even if they are not directly connected.

Gateways offer a number of advantages, including:

• Connectivity: Gateways allow devices on different networks to communicate with each other. This can be important for businesses that need to connect their internal networks to the internet or to other businesses.
• Security: Gateways can be used to provide security for a network. This can help to protect sensitive data from unauthorized access.
• Scalability: Gateways can be scaled to meet the needs of a growing network. This can be important for businesses that are experiencing rapid growth.

Gateways also have a few disadvantages, including:

• Cost: Gateways can be expensive, especially for large networks.
• Complexity: Gateways can be complex to configure and manage.
• Single point of failure: If a gateway fails, it can disrupt communication between different networks.

Modem

A modem is a network device that converts digital data into analog data and vice versa. Modems are used to connect computers to the internet over telephone lines, cable lines, or wireless networks.

There are two main types of modems: dial-up modems and broadband modems.

• Dial-up modems: Dial-up modems use the public switched telephone network (PSTN) to connect to the internet. They are the slowest type of modem, with speeds up to 56 kilobits per second (Kbps).
• Broadband modems: Broadband modems use a high-speed connection to the internet, such as cable, DSL, or fiber optic. They are much faster than dial-up modems, with speeds up to 1 gigabit per second (Gbps).

Advantages:

• Easy to use: Modems are relatively easy to use. Most modems come with a user manual that will walk you through the installation and configuration process.
• Affordable: Modems are relatively affordable. You can purchase a modem for a few hundred dollars.
• Reliable: Modems are reliable devices. They are designed to work for many years without any problems.
• Secure: Modems can be secured with a password. This helps to protect your internet connection from unauthorized access.

Disadvantages:

• Slow speeds: Modems can be slow. Dial-up modems have speeds of up to 56 kilobits per second (Kbps), while broadband modems have speeds of up to 1 gigabit per second (Gbps).
• Limited features: Modems typically have limited features. They may not have features such as built-in Wi-Fi, a firewall, or a parental control filter.
• Single point of failure: If your modem fails, you will lose your internet connection.

Access Point

An access point (AP) is a device that provides wireless connectivity to a local area network (LAN). APs are typically used in homes, businesses, and public spaces to allow Wi-Fi devices, such as laptops, smartphones, and tablets, to connect to the internet.

APs work by broadcasting a wireless signal that devices can use to connect to the network. The AP then routes traffic between the wireless devices and the wired network.

There are two main types of access points:

• Wireless routers: Wireless routers are devices that combine the functions of an AP and a router. Routers are used to connect multiple devices to the internet, and they also provide security features such as firewalls and encryption.
• Standalone access points: Standalone access points do not have routing capabilities. They are typically used in businesses and public spaces where there is already a router present.

There are several benefits to using access points, including:

• Mobility: Access points allow users to connect to the network from anywhere within range of the AP’s signal. This makes it easy for users to move around without losing their internet connection.
• Cost savings: Access points can save businesses money by eliminating the need to run Ethernet cables to each device. This can be especially beneficial in large businesses with a lot of devices.
• Security: Access points can be configured to use security features such as firewalls and encryption to protect data from unauthorized access.

These are just a few of the many types of network devices. The specific devices that are used in a network will depend on the size and complexity of the network.

Nodes in a Network

Nodes in a computer network are the individual devices that are connected to the network. These devices can be network devices, such as switches, routers, and gateways, or they can be endpoint devices, such as computers, printers, and mobile devices. Each node in a network has a unique network address, such as an IP address, which is used to identify and communicate with the device on the network. Nodes can communicate with each other through the use of protocols, such as TCP/IP, and they can share resources, such as files and printers. The number and type of nodes in a network will depend on the purpose and size of the network.

• End Devices
• Intermediary Devices

End devices are the devices that use the network to perform tasks. Examples of end devices include personal computers, laptops, smartphones, tablets, and printers.

Intermediary devices are the devices that connect end devices to each other and to the rest of the network. Examples of intermediary devices include routers, switches, and firewalls.

End devices perform a variety of tasks on a computer network. Some of the most common tasks include:

• Sending and receiving data: End devices use the network to send and receive data, such as emails, files, and web pages.
• Sharing resources: End devices can share resources with each other, such as printers, scanners, and files.
• Collaborating: End devices can be used to collaborate with other users, such as working on a document together or sharing a presentation.

Intermediary devices perform a variety of tasks to keep the network running smoothly. Some of the most common tasks include:

• Routing: Routers direct data traffic between different networks.
• Switching: Switches connect devices on the same network.
• Firewalling: Firewalls protect networks from unauthorized access.
• Congestion control: Intermediary devices can help to prevent congestion on the network.

Conclusion

When it comes to computer networks, network devices are a crucial component in creating and maintaining a functional network. These devices are used to connect multiple computers together and facilitate communication between them.

One common network device is a router, which acts as the central hub for the network. It is responsible for routing data packets between connected devices and forwarding them to their intended destinations. In addition, routers can also provide security features such as firewalls to protect the network from outside threats.

Another important network device is a switch, which is used to connect multiple devices within the network. Switches operate at the data link layer of the network and are responsible for routing data packets between devices within the same network. They are generally faster than routers when it comes to transmitting data between devices.

Finally, there are also network repeaters and extenders, which are used to extend the range of a network. Repeaters are used to amplify or regenerate signals over long distances, whereas extenders use wireless signals to boost the range of a network.

Understanding the various types of network devices and their functions is crucial in creating a functional and efficient computer network. By using the right combination of devices, network administrators can ensure that their networks are secure and that data is transmitted quickly and reliably.

More great stuff related to networking coming soon! Stay tuned and share and subscribe for more!

Access the The Basics of Computer Networks: DNS and IP Address (Next post in Networking) by clicking HERE

Access the OSI and TCP/IP Models (Previous post in Networking) by clicking HERE

This is a multi-part series on DevOps 101. Access the complete DevOps series by clicking HERE