Network Devices

Day 1

Network

A computer network is a digital telecommunications network which allows nodes to share resources.

Nodes are as follows:

Network nodes

Two nodes connected together make a network, so if two PCs are connected, for example, it is already a network.

Client and Server

A client is a device which accesses a service made available by a server. E.g. smartphone, laptop, PC, tablet, etc.

A server is a device which provides a service for clients. Servers are the same devices as clients but what makes them different is their functionality.

client-server

Here, both devices are PCs, so it is a network. However, not both are clients. Since PC1 is requesting information, it is a client, and PC2 is providing it, which makes PC2 a server. So, a client device can be a server as well. Besides that, the same device can be a client in some situations, and a server in other situations.

Switches and Routers

A local area network (LAN) is a collection of devices connected together in one physical location, such as a building, office, or home.

A switch is a device which provides this connectivity in the LAN, not over the internet. Switches have many network interfaces/ports for end hosts to be able to connect(usually 24+). Here are some examples of switches:

catalyst 3650
Cisco Catalyst 3650
catalyst 9200
Cisco Catalyst 9200

A router is a device which provides connectivity between LANs and is used to send data over the internet. Routers have fewer ports than switches. Some examples of routers:

ISR 900
Cisco ISR 900
ISR 1000
Cisco ISR 1000

Firewall

A firewall is a device which monitors and controls traffic based on configured rules. It can be placed inside the network and/or outside the network. These firewalls are network-based hardware devices. But there are host-based firewalls as well. Host-based firewalls are software applications installed in the system. They usually come pre-installed with OS (Operating System). Some firewalls may include more modern and advanced capabilities. Those are called "Next-Generation Firewalls".

Firepower 2100
Cisco Firepower 2100
ASA5506-X
Cisco ASA 5506-X
57KB
Day 1 Flashcards - Network Devices.apkg
42KB
Day 1 Lab - Packet Tracer Introduction.pkt

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