update to 05.Ethernet Lan Switching

01. Network Devices - CCNA.md

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+---
+id: 1771668476-SUCR
+aliases:
+  - 01. Network Devices - CCNA
+tags:
+  - CCNA
+---
+
+# Network Devices
+
+## What is a network
+
+A computer network is a digital telecommunications network which allows nodes to share resources.
+
+### [[Router]]
+
+Is represented with a circle where inside there are 2 horizontal arrow poiting 
+inside and 2 vertical arrow pointing outside
+
+Have fewer network interfaces than switches
+Are used to provide connectivity **between** LANs
+Are therefore used to send data over the Internet
+
+example of [[Cisco]] routers:
+- [[ISR 1000]]
+- [[ISR 900]]
+- [[ISR 4000]]
+
+### [[Switch]]
+
+Is represented with square 4 horizontal 2 poiting to the left and 2 pointing to the right
+
+Switches a used to connect a [[LAN]]
+
+Have many network interfaces/oirts for end hosts to connect to (usually 24)
+Provide connectivity to hosts within the same LAN
+do not provide connectivity between LANs/ over the internet
+
+example of [[Cisco]] switches:
+- [[Catalyst 9200]]
+- [[Catalyst 3650]]
+
+### [[Firewall]]
+
+Is represented with square with a brickwall inside of it
+
+Monintor and control network traffic based on configured rules.
+Can be placed 'Inside' the network, or 'outside' the network
+Are known as 'Next-Generation Firewall' when they include more modern and advanced filtering capabilities
+
+
+example of [[Cisco]] firewalls:
+- [[ASA 5500-X]]
+- [[Firepower 2100]]
+
+#### Host-based firewalls
+
+Are software applications that filter traffic entering and exiting a host machine, like a [[PC]]
+
+
+### [[Server]]
+
+Is represented with square with a computer inside of it
+
+**A device that provides functions or services for clients.**
+
+The same device can be a client in some situations, and a server in other situations.
+
+### [[Client]]
+
+Is represented with square with a monitor inside of it
+
+Can be a computer, a laptop, or a phone
+
+**A client is a device that accesses a service made available by a server.**
+
+### [[Internet]]
+
+Is represented with circle with a cloud inside of it
+
+## Building a network
+
+2 pc connected together create a network
+
+## Quiz
+
+1. Your company wants to purchase some network hardware to which they can plug the 30 PCs in your department. 
+which type of network device is appropriate?
+
+a) A router
+b) A firewall 
+c) A switch
+d) A server
+
+**good answer: c**
+
+2. You received a video file from your friend's [[Apple]] [[iPhone]] using [[AirDrop]]. 
+What was his iPhone functioning as in that transaction?
+
+a) A server
+b) A client
+c) A LAN
+
+**good answer: a**
+
+3. what is your computer or smartphone functioning as while you watch this video?
+
+a) A server
+b) An end host
+c) A client
+
+**good answer: c**
+
+4. Your company wants to purchase some network hardware to connect its separate network together.
+what kind of network device is appropriate ?
+
+a) A firewall
+b) A host
+c) a LAN
+d) A router
+
+**good answer: d**
+
+5. Your company wants to upgrade its old network firewall that has been in use for several years to one that provides more advanced function.
+What kind of firewall should they purchase ?
+
+a) A host-based firewall
+b) A next-level firewall
+c) A next-generation firewall
+d) A top-layer firewall
+
+**good answer: c**