CCNA Learning Journey

Day 1 : Network Devices

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

Servers and Clients

Switches:

• have many network interfaces/ports for end hosts to connect to (usually 24+).
• provide connectivity to hosts within the same LAN (Local Area Network).
• do not provide connectivity between LANs/over the internet.

Routers:

• have fewer network interfaces than switches.
• are used to provide connectivity between LANs.
• are therefore used to send data over the internet.

Firewalls:

• monitor and control network traffic based on configured rules.
• can be placed “inside” the network, or “outside the network”.
• are known as “Next Generation Firewalls” when they include more modern and advanced filtering capabilities.

Host-based firewalls

• are software applications that filter traffic entering and exiting a host machine, like a PC.