CCNA Module 1: Networking Today - Introduction to Networks (ITN)
This is an introduction to the Cisco Networking Academy courses, which can be taken through accredited institutions to obtain Cisco certifications. The first video in the series covers Module 1 of the CCNA, which introduces networks and their impact on daily life. Networks allow for global connections and communication, and have become even more important during the COVID-19 pandemic. Network systems are made up of components such as hosts, servers, and clients, which all work together to provide communication and information sharing.
Introduction to Networks - Module 1: Understanding Networks
Networks affect our lives by enabling communication and interconnectivity, becoming increasingly important during the COVID-19 pandemic
The future generations will be more connected than the current ones, and networks play a crucial role in breaking down global boundaries
Network systems include various components, such as hosts, end devices, and servers
Servers, like email servers, web servers, and file servers, are computers that provide information to end devices and are typically accessed by multiple clients
Networks can be represented on paper and electronic documents using network representations and topologies
Common types of networks include Local Area Networks (LANs), Wide Area Networks (WANs), and Metropolitan Area Networks (MANs)
Internet connections, such as landlines and satellite connections, interconnect networks globally
Reliable networks have four basic requirements: availability, reliability, resiliency, and security
Network trends include Bring Your Own Device (BYOD), online collaboration, video, cloud computing, and network security
Understanding network security threats and solutions is essential for IT professionals in the networking field
Employment opportunities in the networking field include network engineering and network analyst positions
Network Components
Hosts, also known as end devices, are computers or other devices connected to a network
Servers are computers that provide information to end devices and are typically accessed by multiple clients
Network components are defined based on the infrastructure of networks and how they have been put together to create global communication networks
Network Representations and Topologies
Networks can be represented on paper and electronic documents using network representations and topologies
Topologies describe the arrangement of a network, including its nodes and connecting lines
Common Types of Networks
Common types of networks include Local Area Networks (LANs), Wide Area Networks (WANs), and Metropolitan Area Networks (MANs)
Networks can be interconnected globally using internet connections, such as landlines and satellite connections
Reliable Networks
Reliable networks have four basic requirements: availability, reliability, resiliency, and security
Availability refers to the percentage of time that a network is available for use
Reliability refers to the network's ability to transmit data accurately
Resiliency refers to the network's ability to recover from failures
Security refers to the network's ability to protect data from unauthorized access and attacks
Network Trends
Network trends include Bring Your Own Device (BYOD), online collaboration, video, cloud computing, and network security
BYOD refers to the practice of allowing employees to use their personal devices for work purposes
Online collaboration and video tools enable remote work and virtual meetings
Cloud computing allows for the storage and access of data and applications over the internet
Network security is becoming increasingly important as networks become more complex and interconnected
Network Security
Understanding network security threats and solutions is essential for IT professionals in the networking field
Common network security threats include malware, phishing, and denial-of-service (DoS) attacks
Network security solutions include firewalls, intrusion detection systems (IDS), and encryption
IT Professional
Employment opportunities in the networking field include network engineering and network analyst positions
IT professionals in the networking field should have a strong understanding of network components, representations, topologies, and security
Client-Server Model
Client computers send requests to servers to retrieve information (e.g. web pages, emails)
Servers run email, web, and file server software
Clients are the end devices that request services from servers
Servers contain dedicated services that provide those services (e.g. email, web, file)
Peer-to-Peer Networks
Peer-to-peer networks have no central authority
No privilege over anyone, all peers are equal
Most corporate networks do not use peer-to-peer networks due to security and control issues
Peer-to-peer networks must have the exact same operating system to communicate
Peer-to-peer networks are typically not scalable and are only used for simple tasks such as sending data directly to a printer
End Devices
End devices are where messages originate from or are received
Examples of end devices include computers, laptops, and mobile devices
End devices are used to access data on a network
Intermediary Network Devices
Intermediary network devices interconnect end devices
Examples of intermediary network devices include switches, wireless access points, routers, and firewalls
Intermediary network devices are used for management of data as it flows through the network
Note:
In the future, we will go into depth on how the client-server model works and how intermediary network devices manage data flow through the network.
Importance of intermediary devices in a network
Intermediary devices manage the data as it flows through the network
They ensure that the end user at one end gets what they want and the end user at the other end receives exactly what was sent
Network media
Network media allow communication across networks through a medium that allows messages to travel between source and destination
In the past, most network media was made out of metal wires. Today, modern high-speed network communication systems include fiber optics or glass or plastic fibers and wireless transmission
Fiber optics are faster, more reliable, and more secure than metal wires. Wireless transmission is easy to set up and flexible, but it is not as secure and more prone to errors
Network representations and topologies
Network diagrams, also called topology diagrams, use symbols to represent devices within the network
The network interface card (NIC) is a physical connection port that allows you to connect to the network
The physical port and interface are often used interchangeably and are typically associated with the NIC
Network topology diagrams can be put into two different categories: physical topology and logical topology
Types of network topologies
Physical topology refers to the physical layout of a network, including the devices, cables, and connections
Logical topology refers to the way data flows through a network, including the paths and protocols used for communication
Common types of network topologies
Bus topology: all devices are connected to a single cable
Ring topology: all devices are connected to each other in a circular fashion
Star topology: all devices are connected to a central hub or switch
Tree topology: a combination of bus, ring, and star topologies
Mesh topology: each device is connected to every other device in the network
Importance of understanding network topologies
Understanding network topologies can help you design, implement, and troubleshoot a network
Different topologies have different advantages and disadvantages, and choosing the right one depends on the specific needs of the network
Understanding Network Topologies
There are two types of network topologies: physical and logical
Physical topology diagrams illustrate the physical location of intermediary devices and cables
Logical topology diagrams illustrate devices, ports, and addressing schemes of the network
Physical topology is based on the actual physical location of the device
Logical topology is based on how the router or a particular network device separates other devices, regardless of where the device is located
Common Types of Networks
Small home networks: connect a few computers to each other and the internet
Small office/home office (SOHO) networks: enable computers within a home or remote office to connect to a corporate network
Medium to large networks: seen typically in private companies, small companies, and government agencies with a specific location
Worldwide networks: large interconnected global networks such as shipping companies or credit card companies and the internet
Note:
A router is used to logically separate different sections of a network, regardless of where the devices are physically located
Small home networks connect a few devices directly to the internet, while SOHO networks enable computers within a home or remote office to connect to a corporate network
Medium to large networks and worldwide networks are typically found in specific locations such as private companies, small companies, government agencies, and global corporations
Future Topics:
How routers separate network topologies
Common types of network devices
Network protocols and standards
Types of Networks
Small Home Networks: Connects devices within a home
Small Office/Home Office (SOHO) Networks: Connects multiple devices within a small office or home office
Medium to Large Networks: Connects hundreds of thousands of interconnected computers in multiple locations
Worldwide Networks: Connects hundreds of millions of computers worldwide, including the internet
Local Area Network (LAN) vs Wide Area Network (WAN)
LAN: Network infrastructure that spans a small geographical area, administered typically by a single organization or individual, and provides high-speed bandwidth to internal devices
WAN: Network infrastructure that spans a wide geographical area, administered typically by one or more service providers, and provides slower speeds links between the lands
Differences between LAN and WAN
LAN interconnects a limited number of devices in a limited area, while WAN interconnects multiple LANs over a wide geographical area
LAN provides high-speed bandwidth, while WAN provides slower speeds
LAN is typically administered by a single organization or individual, while WAN is typically administered by one or more service providers
Internet
Worldwide collection of interconnected LANs and WANs
Note:
The speed of WAN is getting better with the advancement of fiber optics, but it is typically slower than LAN.
Connection between data centers
Data centers are connected to each other using vans
Vans may use copper wires, fiber optic cables, and even wireless transmission to communicate with each other
Usage of wireless transmission
Wireless transmission is used to communicate between different sites and communities
Satellite communication systems that connect multiple different countries can be considered as a type of wireless network
Internet and its structure
The internet is not owned by an individual or group
Groups such as IETF, ICAN, and IAB are involved in developing and maintaining the structures on the internet
IETF is responsible for standardizing most of the network infrastructure
ICAN is responsible for things like the IP address signing and the global world wide web web addresses
Types of networks
The common types of networks include the intranet, extranet, and internet
Intranet is a private collection of lands and vans internal to the organization and is meant to be accessible only to the organization's members or others within the authorization
Extranet can be used by an organization to provide secure access to their network for individuals who work for a different organization
Key terms for CCNA and CCNP exams
Intranet and extranet are key terms that you should know for your CCNA and CCNP exams
Understanding Internet Connections
Different types of ways to connect to the internet
Home and small office internet connections: cable, DSL, cellular, satellite, dial-up
Cable connections include fiber net networks and other types of specialized cables that provide high bandwidth always-on internet
DSL includes high bandwidth always-on internet connection that runs over a telephone line
Cellular networks allow internet connections to your cell phones, useful especially if you are going somewhere outside and there is coverage available
Satellite networks provide internet connections to rural areas through a direct satellite connection between the satellite itself and your home or small office
Dial-up connections are inexpensive, low bandwidth, but not very reliable and used in some parts of the world
In Canada, most internet connections are either cable or DSL, and also cellular in rural parts of Europe and Canada, satellite communication is used
Business internet connections include dedicated lease lines (T1, T2) that provide very high bandwidth and high availability
Ethernet WAN extends LAN access technology into the WAN, allowing communication between two different locations
These definitions may slightly change as technology advances
Understanding Home and Small Office Internet Connections
Cable connections: high bandwidth, always-on internet offered by television service providers
DSL: high bandwidth, always-on internet connection that runs over a telephone line
Cellular networks: internet connections to your cell phones, useful especially if you are going somewhere outside and there is coverage available
Satellite networks: internet connections to rural areas through a direct satellite connection between the satellite itself and your home or small office
Dial-up: inexpensive, low bandwidth, but not very reliable and used in some parts of the world
Understanding Business Internet Connections
Dedicated lease lines (T1, T2): more expensive but provide very high bandwidth and high availability
Ethernet WAN: extends LAN access technology into the WAN, allowing communication between two different locations
Note:
The technology is moving at a fast pace, and the definitions of these connections may change over time.
In Canada, most internet connections are either cable or DSL, and also cellular in rural parts of Europe and Canada, satellite communication is used.
Additional Note:
In some parts of the world, dial-up internet connections are still being used, and it is important to know how they work and how they are utilized by different users.
In rural areas, satellite communication is being used, and companies like Starlink provide end-users with the option to buy satellite systems that can be hooked up to their roof or something to get the internet.
Types of Corporate Business Connections
Leased lines, Digital Subscriber Lines (DSL) such as Business DSL, SDSL (Symmetric Digital Subscriber Lines), and Satellite connections
These connections provide higher bandwidth, dedicated connections, and managed services such as dedicated lines for voice, web access, or specific software systems
Converged Networks
Converged networks carry multiple services on a single link
They use the same set of rules and standards, and technologies such as VLAN, ACL (Access Control List), and QoS (Quality of Service) to ensure proper delivery of data
Cisco Packet Tracer
Used in this course for CCNA and CCNP studies
Allows for the creation of network representations and has modules for labs to learn network systems and engineering
Reliable Network Architecture
Based on multiple concepts coming together to build a better system
Will be discussed in the next section of this module
Affiliate Network Architecture
Refers to the technologies that support the infrastructure for data movement across the network
Can be made reliable by utilizing four basic characteristics: fault tolerance, scalability, quality of service (QoS), and security
Fault Tolerance
A fault tolerance network limits the impact of a failure by limiting the number of affected devices
Provides redundancy by implementing a packet switch network, allowing for multiple paths for data to take
Increases fault tolerance by splitting traffic into packets and sending them over different paths to the same destination
Scalability
A scalable network can expand quickly and easily to support new users and applications without impacting the performance of existing users
Requires the use of accepted standards and protocols to ensure easy and quick expansion
Allows for the addition of new devices or intermediate devices without impacting the performance of existing users
Quality of Service (QoS)
QoS ensures that the network can prioritize certain types of data and allocate resources accordingly
This is important for real-time applications such as video conferencing or VoIP, which require a certain level of performance to function properly
Security
Security measures are in place to protect the network and its data from unauthorized access or malicious attacks
This can include measures such as encryption, firewalls, and access controls
All of these characteristics come together to create a reliable network architecture that can handle the demands of modern applications and users.
Quality of Service (QoS)
QoS is very important for services that cannot take latency or cannot tolerate latency, such as voice and live video transmissions
If packets are lost in these transmissions, it can cause confusion and make the transmission completely useless
QoS is used to ensure the reliable delivery of content for all users by managing the flow of data and prioritizing certain traffic
Examples of poor QoS
High demand for bandwidth than the available bandwidth in a particular system can cause constant breaks and buffering in live video transmissions
If QoS is not implemented in a home router or modem, bandwidth will be split randomly and can cause delays in voice packets
Network Security
There are two main types of network security: network infrastructure security and information security
Network infrastructure security includes physical security of network devices and preventing unauthorized access to those devices
Information security is the protection of data transmitted over the network through encryption and authentication
Goals of network security
The three goals of network security are confidentiality, integrity, and availability
Importance of QoS in network security
QoS is one of the primary mechanisms used to ensure the reliable delivery of content for all users, which is important for network security
With QoS policy in place, a router can prioritize certain traffic, such as voice or video, over other traffic, such as file downloads, to ensure the reliable delivery of those packets
Definition of Data Integrity
Data integrity refers to the accuracy, consistency, and completeness of data during its entire lifecycle.
It ensures that the data has not been tampered or altered during the transmission.
Importance of Data Integrity
It assures that the data has not been tampered or altered during the transmission.
The data that needed to be accessed can be accessed in a timely and reliable manner by all the authorized users.
Balancing Data Integrity with Data Availability
Confidentiality, integrity, and availability (CIA) are the three key principles of information security.
Data availability is important for organizations and consumers in modern day, especially with the rise of remote work and online collaboration.
Managing Data Integrity
Administrators can protect the software and hardware using encryption and logging authentication systems.
Regular backups and disaster recovery plans can also help ensure data integrity.
Recent Network Trends
Bring Your Own Device (BYOD) allows users to use their own devices, giving them opportunities and greater flexibility.
Online collaboration allows users to collaborate and work with others over the network on joint projects.
Cloud computing allows organizations and consumers to buy cloud services instead of having their own physical data centers.
Bring Your Own Device (BYOD)
BYOD allows users to have the freedom to use their personal tools to access information and communicate.
Any device with any ownership can be used by anyone anywhere else on your network as long as they have the authorizations and authentications to access resources within your network.
Online Collaborations
Online collaborations allow users to collaborate and work with others over the network on joint projects.
This is how the internet first started when in the United States a bunch of universities got together to share resources and information.
History of the Internet and Collaboration Tools
The Internet began as a network that connected research institutions for scientific collaboration
Modern collaboration tools include Cisco Webex, Microsoft Teams, and Office 365
These tools allow for real-time collaboration on documents and instant communication
Importance of Collaboration in Business and Education
Collaboration is a high priority for businesses and the educational research sector
Cisco Webex Teams is a multi-functional tool used by large companies, organizations, and institutions
Video Communication
Video communication is becoming more important as more people work remotely
Tools like Cisco Telepresence allow for the sharing of physical materials and data during video calls
Cloud Computing
Cloud computing allows for the storage and backup of data and files on servers over the Internet
It allows for access to applications and data from any device, anywhere in the world
Cloud computing is made possible by large data centers, and there are different types including public and private clouds
Benefits of Cloud Computing
Cloud computing allows smaller companies to outsource their storage and physical services
It increases reliability and allows for access to data and services from anywhere
Understanding Cloud Types
A private cloud is a type of cloud system that is used by a single organization and is not shared with any other entities
A hybrid cloud is made up of two or more cloud types, such as a combination of custom and public clouds, that are interconnected using a semi-architecture
An example of a hybrid cloud is the University of Calgary's Unicity Cal initiative, where professors and researchers interact on a custom cloud while the public can access a public cloud to collaborate
Custom Clouds
Custom clouds are built to meet the needs of specific industries, such as healthcare, media, or oil and gas
They can be either private or public, and are useful for accessing data from remote locations with high reliability
An example of a custom public cloud is a rural town in Japan that created a cloud system for public schools to access information
Smart Homes Technology
Smart homes technology is a growing trend that allows everyday appliances to be integrated and interconnected with other devices
Examples of smart home technology include automation tools that allow users to control lights, check if garage doors are open, and even cook meals based on schedules
Power Line Networking
Power line networking is a technology that has been around for a long time and allows devices to connect to a LAN using electrical cables and a power line standard adapter
It is useful for connecting devices that are far away from a network hub or router, or in places where running data cables is not feasible
Wireless Broadband
Wireless broadband is another option for accessing the internet, in addition to DSL and cable
Connecting Homes and Small Businesses to the Internet
Wireless Internet Service Providers (WISPs) commonly found in rural environments
High-powered communication broadband towers send signals over a wide area
Wireless Broadband for home and small businesses uses cellular technology
Antenna installed outside of the house provides wireless or wired connectivity
Network Security
Important for all networks, regardless of size
Security measures must balance data protection and quality of service
Involves many protocols, technologies, devices, tools, and techniques
Security Threats
External threats: viruses, worms, Trojan horses, spyware, adware, zero-day attacks, threat actor attacks, denial of service attacks, data interception and theft, identity theft
Internal threats: lost or stolen devices, accidental misuse by an employee, employees with intention of harming the organization
Security Solutions
Implemented in multiple layers using more than one security solution
Network security components for home or small office networks: anti-viruses, anti-spyware software, firewall filtering in intermediate devices or separate firewall devices
Large networks have additional security requirements such as dedicated firewall systems, intrusion prevention systems, and virtual private networks (VPNs)
Network Security Study
Begins with a clear understanding of network security principles and best practices
Continuous learning and staying up-to-date on new threats and security solutions is essential
Understanding Networking and Career Opportunities
Understanding the underlying infrastructure of switching and routing is crucial in networking
CCNA and CCNP certifications demonstrate knowledge of foundational technologies and ensure relevance with next generation technologies
New DevNet certifications validate software development skills for networking jobs
Employment opportunities can be found on the NetAcad website, local websites, and local companies
Cisco Network Academy students and alumni can make connections on the Cisco website
Understanding Networks and Devices
All computers connected to a network and participating in network communication are classified as hosts
Diagrams of networks use symbols to represent devices and connections
Logical diagrams provide an easy way to understand how devices connect in a large network
Local Area Networks (LAN) and Wide Area Networks (WAN) are two types of network infrastructures
Network architecture refers to the topologies, services, and protocols that move data across the network
Network Architecture Characteristics
Fault tolerance, scalability, QoS (Quality of Service), and security are the four basic characteristics of a network architecture
Networking Trends
Bringing Your Own Device (BYOD), online collaboration, video communications, and cloud computing are recent networking trends
Network Security
Larger networks and corporate networks use antiviruses, anti-spyware, and firewall filtering
Other security requirements include dedicated firewall systems, access control lists (ACLs), intrusion prevention systems (IPS), and virtual private networks (VPN)
Certifications and Skills
CCNA certification demonstrates knowledge of foundational technologies
CCNP certification ensures relevance with skills needed for adaption of next generation technologies
DevNet certifications validate software development skills for networking jobs
Finding Networking Jobs
Employment opportunities can be found on the NetAcad website, local websites, and local companies
Cisco Network Academy students and alumni can make connections on the Cisco website
Cisco Talent Bridge matching engine can be used to find opportunities
Overview of badges and certifications
The badges displayed represent the completion of a module on network systems
They show that the learner has obtained knowledge in the basics of network systems and practical applications
The knowledge gained from this module can be applied to daily life
CCNA and CCNP certifications can be obtained through registered organizations that administer the courses and exams
Additional resources and future modules
Additional supporting videos will be posted in the future
New modules in this series will also be published in the near future
Listening to different people talk about the same slide set allows students to gain more in-depth knowledge of network systems by understanding the concepts in different ways
Copyright information
The slide set used in this explanation is provided by Cisco and is copyrighted by the company
The information is free to use for educational purposes
Encouragement to engage with the content
The speaker encourages the audience to subscribe, give a thumbs up, and stay tuned for the next module which will be published in a few days
CCNA Module 3: Protocols and Models: Introduction to Networking
This module by Cisco introduces protocols and models for network communication. Protocols, which are rules for communication, enable devices to access local and remote network resources. These rules ensure that devices can identify their place in the network and communicate effectively. Communication involves three elements: a source or sender, a destination or receiver, and a channel or media that provides the path for communication. Protocols govern all communications and may vary depending on the specific protocol being used. The lecture also covers data encapsulation, standard organizations, and reference models like TCP/IP and OSI.
Introduction to Protocols and Models in Networking
Learn about protocols and models that enable devices to access local and remote network resources
Understand the importance of rules and protocols in network communication
Learn about the role of standard organizations in enforcing protocols
Understand the concept of data encapsulation and data access
Additional slides on the OSI model will be included for a better understanding
Devices in a Bubble Video
A link to a Cisco video explaining the protocols that devices use to communicate will be provided
The video covers the basics of network communication
Communications Fundamentals
Networks can vary in size and complexity
Three elements of network communication: source, destination, and channel
Communications are governed by protocols, which are rules that dictate how communication occurs
Elements of Communications Protocols
A message needs to be sent
The message must be formatted according to the rules of the protocol
The message must be sent over a specific channel or medium
The message must be received and interpreted by the destination
Examples of Protocols
TCP/IP model
ISO model
Standard organizations such as IEEE and IETF
Data Encapsulation
Data is wrapped in a header that contains information about the data
The header is used to guide the data through the network
Data access is the ability for a device to access resources on a network
Localhost is used to access resources on the same device
Cisco Slice Set
Additional information about the Cisco slice set will be provided
The slice set is a set of guidelines for network communication
OSI Model
The OSI model is a framework for understanding how data is transmitted over a network
It consists of seven layers: physical, data link, network, transport, session, presentation, and application
Each layer has a specific function in the transmission process
Conclusion
Understanding protocols and models is essential for network communication
Standard organizations play a crucial role in enforcing protocols
Data encapsulation and data access are important concepts in network communication
The OSI model provides a framework for understanding how data is transmitted over a network
Understanding Communication through a Network
Communication involves a message being sent from a source, through a transmitter, transmitter medium, and receiver, and then reaching a destination
Established rules or agreements, such as a common language and grammar, must be used to govern the conversation
The first message in this example is difficult to read due to poor formatting, while the second message is properly formatted and easier to understand
Protocols for Communication
Protocols must account for the following requirements: an identified sender and receiver, a common language and grammar, proper formatting, speed and timing of delivery, and confirmation or acknowledgement of the message
Network protocol requirements include common computer protocols such as message encoding, message formatting and encapsulation, message size, message timing, and message delivery options
Message Encoding
Encoding is the process of converting information into another acceptable form of transmission, decoding reverses this process
The encoding process takes the message from the source and encodes it so that it can be transmitted through different layers and received by the destination
Message formatting and encapsulation: when a message is sent, it must use specific formats or structures depending on the type of message and the channel it is used to deliver the message
Examples of Message Formatting and Encapsulation
Email: specific email message format such as POP or SMTP
Physical message: paper and pencil or paper and pen
Website or social media: HTTP or HTTPS protocol
Message Size
The size of the message is important to ensure that it can be transmitted and received without issues
The message size should not exceed the maximum limit set by the network protocol
Message Timing
The timing of the message is important to ensure that it is received in a timely manner
The message should be sent and received within the agreed-upon time frame to avoid delays or loss of the message
Message Delivery Options
There are different message delivery options such as best effort, reliable, and guaranteed delivery
Best effort delivery: the message is sent, but there is no guarantee that it will be received
Reliable delivery: the message is sent and an acknowledgement is received when it is received
Guaranteed delivery: the message is sent and an acknowledgement is received, and if the message is not received, it is re-sent
Data Packets
Data packets have encapsulated the AI's information for transmission through a network
They contain various pieces of information, including version, traffic class, flow label, destination IP, source IP, payload length, next header, and hop limit
When an email or message is sent, it is converted to bits and encoded into patterns of light, sound, or electrical impulses for transmission
At the destination, the signal is decoded to interpret the message
Message Size and Encoding
The message size includes the flow control, response timeout, and access method
The flow control manages the rate of data transmission and defines how much information can be sent and the speed at which it can be delivered
The response time manages how long a device waits when it does not hear a reply back from the destination
The access method determines when someone can send a message
Message Timing
The message timing includes the flow control, response timeout, and access method
The flow control manages the rate of data transmission and defines how much information can be sent and the speed at which it can be delivered
The response time manages how long a device waits when it does not hear a reply back from the destination
The access method determines when someone can send a message
Access Method
The access method determines when someone can send a message
There may be various rules and protocols in place to regulate when and how a device can send a message
Error Messages
Error messages, such as response timeout, may be displayed when there are too many requests going into a server or if there is a problem with the transmission of data
Network Transmission
Data is transmitted through a network by converting the message to bits and encoding it into patterns of light, sound, or electrical impulses
The encoded message is then sent through the network to the destination, where it is decoded and interpreted
IP Addresses
The source and destination IP addresses are included in the data packet to ensure that the message is sent to the correct location
Payload Length
Next Header
The next header indicates the type of data that is being transmitted
Hop Limit
The hop limit indicates the maximum number of hops (or routers) that the message can pass through before it is discarded
Traffic Class
The traffic class indicates the priority of the message and can be used to determine the order in which messages are transmitted
Flow Label
The flow label is used to identify a specific flow of messages and can be used to manage the transmission of those messages
Understanding Light
Light is electromagnetic radiation that is visible to the human eye
It has a wavelength of 400-700 nanometers and a frequency of approximately 430-770 terahertz
Light waves are electromagnetic waves that travel through the vacuum of space
They are produced when an object vibrates, and they travel at the speed of light
Properties of Light
Light has both wave-like and particle-like properties
It exhibits wave-like properties when it interferes with other light waves
It exhibits particle-like properties when it is emitted or absorbed by matter
Speed of Light
The speed of light in a vacuum is 186,282 miles per second (299,792 kilometers per second)
The speed of light can be measured with a laser beam or a light-emitting diode
Message Timing in Networks
There are three sections in message timing: flow control, response timer, and access method
The message delivery options include unicast, multicast, and broadcast
Flow control, response timer, and access method work together to control message timing and access control in networks
Message Delivery Options
Unicast is a one-to-one communication
Multicast is a one-to-many communication
Broadcast is a one-to-all communication
Protocol
A protocol is a set of rules to ensure successful host-to-host communication
Network protocols define a common set of rules that can be implemented on devices in software
Understanding Network Protocols
A network protocol is a set of rules and formats that devices use to communicate with each other
It enables two or more devices to communicate over one or more networks
Examples of network protocols include addressing, reliability, flow control, sequencing, error detection, and application interface
Network protocols have one or more functions associated with them
The network requires the use of several protocols, not just one
Importance of Agreed Upon Protocols
Devices must agree upon protocols to communicate with each other, just like people must agree upon a language to communicate
If the protocols are not agreed upon, there will be miscommunication and the communication will fail
Example of Protocol Functions
HTTP (Hypertext Transfer Protocol) governs the way a web server and a web client interact with each other
TCP (Transmission Control Protocol) manages the individual conversations, provides guaranteed delivery, and manages flow control
IP (Internet Protocol) delivers messages globally from the sender to the receiver
Ethernet delivers the message from the network interface card to another network interface card on the same ethernet local area network
Protocol Suits
Protocols must be able to work with other protocols
A protocol suit is a group of interrelated protocols necessary to perform a communication function
Protocols are viewed in terms of layers, with lower layers concerned with moving data and providing services to upper layers
Note:
The above summary is based on the provided text, which is a spoken explanation of network protocols and their functions. It is not a direct transcription, but an attempt to summarize and organize the information in a clear and concise manner.
Communication Protocols
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There are several communication protocols used in the network engineering industry
The most common protocol suite is the Internet Protocol Suite (TCP IP) and the Open Systems Interconnection (OSI) protocols
Proprietary protocols such as AppleTalk and Novell Netware also exist
TCP IP and OSI model are the most commonly used protocols
TCP IP operates at the application, transport, and internet layers, while the OSI model is divided into different categories
TCP IP protocols include HTTP, DNS, DHCP, FTP, TCP, UDP, and Ethernet or WLAN for network access
TCP IP is an open standard protocol that is freely available to the public and used by vendors
It ensures interoperability between different devices and vendors, such as a Cisco switch and a D-Link switch
How Communication Works with TCP IP
The application layer includes HTTP for web access
The transport layer includes TCP for transmission control
The internet layer includes IP for addressing and routing
The network access layer includes Ethernet for physical connections
Data is transmitted from the application layer down to the network access layer and sent over the network
The process is reversed at the receiving end, with data being received at the network access layer and transmitted up to the application layer
TCP IP ensures that data is transmitted and received in the correct order and that any lost packets are retransmitted
Examples of Communication with TCP IP
A user accesses a website using HTTP
The web browser sends a request to the web server using TCP
The web server responds with the website data using TCP
The data is transmitted over the internet using IP
The data is received by the user's device and transmitted up to the web browser using Ethernet or WLAN
The web browser displays the website to the user
TCP/IP Layers and their functions
TCP/IP model consists of four layers: Application, Transport, Internet, and Network Access
Application layer includes protocols such as DNS, FTP, SMTP, etc.
Transport layer includes TCP and UDP protocols
Internet layer includes IP protocol
Network Access layer includes protocols for different types of network interfaces
Example of communication using TCP/IP model
A web server encapsulates and sends a web page to a client using TCP/IP communication process
The packet includes Ethernet, IP, TCP, and data
The client de-encapsulates the web page for the web browser
Standard organizations for internet and TCP/IP protocols
Internet Society (ISOC) promotes the open development and evolution of the internet
Internet Architecture Board (IAB) is responsible for the management and development of internet standards
Internet Engineering Task Force (IETF) develops and maintains internet and TCP/IP technologies
Internet Research Task Force (IRTF) focuses on long-term research related to internet and TCP/IP protocols
Internet Corporation for Assigned Names and Numbers (ICANN) coordinates the IP address allocation, management of domain names, and assignment of other information
IANA (Internet Assigned Numbers Authority) is responsible for the management of IP address allocation, domain names, and other internet protocol resources
Understanding the role of these organizations is important for understanding how the internet and TCP/IP protocols are standardized and developed.
Overview of Network Standards and Reference Models
Multiple organizations manage electronic and communication standards, such as IEEE and TIA
These standards include IP address allocation, domain name management, and protocol identifiers
Reference models, such as the OSI and TCP/IP models, are used to demonstrate complex network concepts with diagrams
The OSI Model
The OSI model has seven layers: application, presentation, session, transport, network, data link, and physical
The data link and physical layers overlap in the OSI model
The OSI model is beneficial for protocol design as it defines a set of rules for protocols at each layer
The TCP/IP Model
The TCP/IP model has four layers: application, transport, network, and network access
Some protocols, such as Ethernet, overlap between different layers in the TCP/IP model
Benefits of Using a Layered Model
Layered models assist in protocol design by defining a set of rules for protocols at each layer
They also provide a clear and defined interface between layers
Examples of Protocol Suites
DHCP, HTTP, DNS, FTP are examples of protocols at the top layer of the OSI and TCP/IP models
IPv4, IPv6, ICMP, ICMPv6 are examples of protocols at the network layer of the TCP/IP model
Ethernet, Wi-Fi, SONET are examples of protocols at the network access layer of the TCP/IP model
The OSI Reference Model
The OSI (Open Systems Interconnection) reference model is a conceptual model that divides network communication into seven layers
It was developed by ISO in the 1980s to describe standards for inter-computer communication
It helps break down network functions and troubleshoot issues
It creates standards for equipment manufacturing and allows vendors to focus on specialized areas of network
The seven layers of the OSI model are: Application, Presentation, Session, Transport, Network, Data Link, and Physical
Each layer has a specific function and communicates with the layers above and below it
The Application Layer
The topmost layer of the OSI model
It is the interface used by applications
Examples of application layer protocols include HTTP, FTP, SMTP, and DNS
It provides services for process-to-process communication
It is responsible for providing a common language to describe networking functions and capabilities
The Presentation Layer
The fourth layer of the OSI model
It provides a common representation of data transferred between application layers
It is responsible for data conversion, data compression, and data encryption
It ensures that data is in a format that can be understood by the receiving device
The Session Layer
The fifth layer of the OSI model
It provides services to the presentation layer and manages data exchange and transfer
It is responsible for establishing, maintaining, and ending communication sessions between applications
It ensures that data is exchanged in a reliable and secure manner
The Transport Layer
The fourth layer of the OSI model
It provides services to the session layer and is responsible for end-to-end communication between applications
It is responsible for segmentation and reassembly of data, flow control, and error recovery
It ensures that data is delivered reliably and efficiently between applications
The Network Layer
The third layer of the OSI model
It provides services to the transport layer and is responsible for routing data between networks
It is responsible for logical addressing, routing, and congestion control
It ensures that data is delivered to the correct destination on the network
The Data Link Layer
The second layer of the OSI model
It provides services to the network layer and is responsible for data transfer between devices on the same network
It is responsible for physical addressing, error detection and correction, and flow control
It ensures that data is transmitted reliably between devices on the same network
The Physical Layer
The bottommost layer of the OSI model
It provides services to the data link layer and is responsible for the physical connection between devices
It is responsible for data encoding, transmission, and reception
It ensures that data is transmitted and received reliably over the physical medium
The OSI model fosters competition by allowing products from different vendors to work together, preventing technology or capability changes in one layer from affecting the other layers or above, and providing a common language to describe networking functions and capabilities.
It fosters competition by allowing products from different vendors to work together
Prevents technology or capability changes in one layer from affecting the other layers or above
Provides a common language to describe networking functions and capabilities
It is important to understand the OSI model for the Cisco class as it is a seven-layer model that conceptualizes data communication and helps break down network functions, troubleshoot issues, and create standards for equipment manufacturing.
It is important to understand the OSI model for the Cisco class
It is a seven-layer model that conceptualizes data communication
Helps break down network functions, troubleshoot issues, and create standards for equipment manufacturing
It is important to memorize the layers of the OSI model and their functions as it will help you recall them during an exam.
Memorize the layers of the OSI model and their functions
Will help you recall them during an exam
The Application Layer
This layer provides network access to applications such as your FTP client or Google Chrome
When you access a website like sunridge.com using HTTPS, your Google Chrome browser is using the application layer to access the data
The Presentation Layer
This layer is used for data formatting such as HTML, JPEG, or MP3
It uses encryption services for online banking and data compression
The Session Layer
This layer controls the dialog between computers and starts and ends sessions
It keeps a session separate to prevent data clashes or corruption
The Transport Layer
This layer describes how data is sent reliably or unreliably
Well-known services such as TCP and UDP operate in this layer, and firewalls typically operate here as well
The Network Layer
This layer is known as the logical addressing layer and contains IP addresses
Routers operate at this layer, which is layer number three
The Data Link Layer
This layer is a layer number two, located just below the network layer
It is responsible for error-free transfer of frames from one node to another
Note:
The above summary is a simplified explanation of the different layers of the OSI model
For a more in-depth understanding, further study is recommended
Overview of Data Encapsulation
Data encapsulation is the process of preparing messages for transmission through a network
It involves breaking up messages into smaller units (segmenting) and interleaving multiple streams of segmented data (multiplexing)
Benefits of Segmenting Messages
Increases speed by allowing large amounts of data to be sent over the network without tying up a communications link
Increases efficiency by only requiring segments that failed to reach the destination to be re-transmitted, not the entire data stream
Comparison of OSI and TCP/IP Models
The OSI model has more layers than the TCP/IP model, with the network access and application layers of the TCP/IP model being divided into multiple layers in the OSI model
The OSI model specifies which protocol to use when transmitting over a physical medium, while the TCP/IP model does not
Important Points for Exams and Quizzes
The OSI model is the most important model for this course, but students should also be familiar with the TCP/IP model
The OSI model's network access and application layers are divided into multiple layers in the TCP/IP model
The OSI model specifies procedures for accessing the media and physical means for sending data over a network, while the TCP/IP model does not
Packet Tracer Simulation Activity
There is a Packet Tracer simulation activity in the NetAcad that students should work on to understand the layers and how they work
A video on this particular Packet Tracer TCP and OSI model investigation will be made in the future
Explanation of Networking Layers
The network includes the IP address and the data link includes the MAC address
The data link layer ensures the data is error-free and devices such as switches operate in this layer
The network layer includes the IP address and routers operate in this layer
The physical layer provides access to the cable and electrical signals and includes the media such as fiber optics or electrical wires
Data Encapsulation
It is a top-down process where each layer adds its own information to the data
The level above processes the data and passes it down to the next level of the model
This process is repeated until it is sent out as a bit stream
An example of data encapsulation is a web server sending data to an end client
As the data moves up the stack, each layer strips off its header and passes it up to the next level until it is a data stream that the application can process
Protocol Data Units (PDUs)
A PDU has a different name to reflect its new functions when things change during the transmission
In this course, PDUs are named according to the protocols of the TCP/IP model or the OSI model
Examples of PDUs are data, segment, packet, frame, and bits
Each layer of the OSI model has its own PDU
Layer 7: data, Layer 6: data, Layer 5: data, Layer 4: segment, Layer 3: packet, Layer 2: frame, Layer 1: bits
De-encapsulation
It is the opposite of encapsulation
As the data moves up the stack, each layer strips off its header and passes it up to the next level until it is a data stream that the application can process
An example of de-encapsulation is the system receiving bits and breaking it down to frame, packet, segment, and data
Interaction of Protocols
Application protocol includes hypertext transfer protocol (HTTP) and transport protocol includes transmission control protocol (TCP) or user datagram protocol (UDP)
These protocols interact with each other to ensure the data is transmitted and received correctly
Understanding the OSI Model and Data Link Layer
The Internet Protocol (IP) is a set of rules that govern the format of data sent over the internet
It includes protocols such as IP, Network Access Protocols, Data Link, and Physical Layers
Data Link layer is responsible for delivering data from one network interface or Network Interface Card (NIC) to the next on the same network
It includes addressing, such as the Data Link layer source and destination address, and the Network layer source and destination addresses
The Transport layer has the destination and source address or the port numbers
Upper layer has the encoded application data
IP Packet
An IP packet contains two IP addresses: the source IP address and the destination IP address
The source IP address is the IP address of the sending device, and the destination IP address is the IP address of the receiving device
An IP address contains two parts: the network portion and the host portion
The network portion, also known as the prefix, indicates the network group which the IP address is a member
The host portion, also known as the interface ID, identifies a specific device within a group
IP Addressing
Devices on the same network will have the same number in the network portion of the address but different numbers in the host portion
For example, two devices on the same network may have IP addresses of 192.168.1.110 and 192.168.1.9
Terminology
An "octet" is a term used to describe a group of 8 binary digits, or bits, in an IP address
IPv4 addressing uses 4 octets, and IPv6 addressing uses 16 octets
Note:
The above summary is a simplified explanation of the OSI model and IP addressing. For a more in-depth understanding, it is recommended to study the OSI model, IP addressing, and subnetting in more detail.
IPv4 Configuration
Devices on the same network will have the first couple of octets the same and the last one different
Mac addresses are physical addresses embedded into the physical ethernet nic
The source mac address will be that of the originator on the link, the destination mac address will always be the same link as the source
Role of the Data Link Layer
When devices are on the same ethernet network, the data link frame will use the actual mac address of the destination nic
The source mac address will be that of the originator on the link, the destination mac address will always be the same link as the source
Network Layer Addresses
The role of the network layer addresses comes into play when the source and the destination have different network portions, meaning they are on a different network
When the final destination is remote, layer 3 will provide layer 2 with the local default gateway ip address, also known as the route address
Default Gateway
The default gateway or dgw is the router interface ip address that is part of this lan and will be the door or the gateway to all other remote locations
All devices on the lan must be told about this address or their traffic will be confined to the lan only
OSI Model
The different layers of the OSI model are being used in this scenario: layer 1 (physical), layer 2 (data link), layer 3 (network), and layer 7 (application)
Note:
The above summary is based on the provided text, which contains some incomplete sentences and lacks some context. It is always recommended to have proper and complete sentences for better understanding and summarization.
Understanding Data Link Layer Addressing in Networking
A computer (PC) is connected to a switch, but the default gateway (DGW) is located at a different point in the network, indicated by an orange arrow.
Data link addressing is local addressing, meaning it has a source and destination for each segment or hop of the journey to the destination.
MAC (Media Access Control) addressing is used for the first segment, with the source being the PC's network interface card (NIC) and the destination being the default gateway interface of the first router.
The source and destination MAC addresses change as the data travels through different routers, but the Layer 3 addressing (IP address) remains the same and does not change.
The main concept to understand in this beginning networking course is that the source and destination addresses change in the data link layer as the data travels through different routers.
The packet is not modified, but the frame is changed, meaning the Layer 2 MAC addressing changes, but the Layer 3 IP addressing remains the same.
Understanding the Changes in Source and Destination Addresses
As the data travels from the source to the destination, the source and destination MAC addresses change at each hop, but the IP addresses remain the same.
For example, the source MAC address changes from the PC's NIC to the first router's exit interface, and then to the second router's exit interface, and so on.
Similarly, the destination MAC address changes from the first router's interface to the second router's interface, and so on, until it reaches the final destination.
The IP addresses, however, do not change and remain the same throughout the journey.
Understanding the Role of Routers in Data Transmission
Routers are used to direct the data from the source to the destination by receiving the frame from one interface and sending it out through another interface.
Each router interface has its own MAC address, which is used as the destination MAC address for the incoming frame and as the source MAC address for the outgoing frame.
The IP addresses, on the other hand, remain the same and are used to identify the source and destination of the data in the network layer.
Understanding the Difference between Layer 2 and Layer 3 Addressing
Layer 2 addressing (MAC addressing) is used for local addressing within a segment or hop of the network, and it changes as the data travels through different routers.
Layer 3 addressing (IP addressing) is used for global addressing and remains the same throughout the journey from the source to the destination.
The main difference between the two is that Layer 2 addressing is used for local communication within a segment, while Layer 3 addressing is used for global communication in the network.
Understanding the Importance of Data Link Layer Addressing
Data link layer addressing is important for the correct transmission of data in a network.
The source and destination MAC addresses are used to identify the devices involved in the communication and to ensure that the data is sent to the correct device.
Understanding how the source and destination addresses change in the data link layer is essential for troubleshooting and managing a network.
Concept of MAC and IP addresses
MAC addresses change from hop to hop in a network, while IP addresses (L3) remain the same as it is a global address
The ultimate destination is the web server, but L2 MAC addressing changes from one segment to the next
Importance of understanding protocols
Protocols have specific requirements such as message encoding, formatting, encapsulation size, timing, and delivery options
Protocols work together in a protocol suite, such as the TCP/IP protocol suite used for internet communication
Standardization organizations
Standardization organizations encourage interoperability, competition, and innovation
Examples include IEEE, IETF, and ISO, which have standardized networking devices and protocols
Reference models
The TCP/IP and OSI models are used to understand networking concepts
The OSI model has seven layers, while the TCP model has four layers
For this course, it is important to understand both models, but the OSI model is more important than the TCP model
Data encapsulation
Data takes a specific form at any layer, called the Protocol Data Unit (PDU)
There are five different PDUs used in the data encapsulation process: data, segment, packet, frame, and bits
Data access (L2 and L3) provides addressing to move data through the network
The way layers handle addressing depends on whether the source and destination are on the same network or not
Summary
It is important to understand the rules and protocols required for sending messages across a network
Standardization organizations have played a crucial role in the development and implementation of networking devices and protocols
Understanding the reference models, such as the TCP and OSI models, is essential for understanding networking concepts
Data encapsulation and addressing are important concepts to understand for network communication
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