Networking ( Module 1 )

1.1 Networks Affect our Lives

Advancements in networking technologies are helping to create a world in which national borders, geographic distances, and physical limitations become less relevant. The internet has changed the manner in which our social, commercial, political, and personal interactions occur.

1.7 Network Trends

BYOD means any Device, with any Ownership, used Anywhere. collaboration: "the act of working with another or others on a joint project." Collaboration tools, like Cisco WebEx, give employees, students, teachers, customers, and partners a way to instantly connect, interact, and achieve their objectives. video used for communications, collaboration, and entertainment cloud computing allows us to access and store data and backup up an entire drive on servers over the internet. Only large organizations use privately built data centers to house their data and provide services to users because they are very expensive to build and maintain Smaller organizations handle cloud computing and data storage by reducing the overall cost of ownership by leasing server and storage services from a larger data center organization in the cloud. cloud providers would store data in distributed data centers instead of storing all the data of a person or an organization in one data center for Security, Reliability, and Fault tolerance. four primary types of clouds: a. Public clouds - Cloud-based applications and services offered in a public cloud are made available to the general population. Services may be free or are offered on a pay-per-use model, such as paying for online storage. The public cloud uses the internet to provide services. b. Private clouds - Cloud-based applications and services offered in a private cloud are intended for a specific organization or entity, such as a government. A private cloud can be set up using the organization's private network, though this can be expensive to build and maintain. A private cloud can also be managed by an outside organization with strict access security. c.Hybrid clouds - A hybrid cloud is made up of two or more clouds (example: part private, part public), where each part remains a distinct object, but both are connected using a single architecture. Individuals on a hybrid cloud would be able to have degrees of access to various services based on user access rights. d. Community clouds - A community cloud is created for exclusive use by specific entities or organizations.: a. The differences between public clouds and community clouds are the functional needs customized for the community. ex: healthcare organizations must remain compliant with policies and laws (e.g., HIPAA) that require authentication and confidentiality. Community clouds are used by multiple organizations that have similar needs and concerns. Community clouds are similar to a public cloud environment, but with set levels of security, privacy, and even regulatory compliance of a private cloud. Smart home technology integrates into every-day appliances, which can then connect with other devices to make the appliances more 'smart' or automated. powerline networking sends information by sending data on certain frequencies. Powerline networking is especially useful when wireless access points cannot reach all the devices in the home. Powerline networking is not a substitute for dedicated cabling in data networks. However, it is an alternative when data network cables or wireless communications are not possible or effective. Powerline networking is? : especially useful when wireless access points cannot reach all the devices in the home. Powerline networking is not a substitute for dedicated cabling in data networks Wireless Internet Service Provider (WISP) operates: its an Internet Service Provider that connects subscribers to a designated access point or hotspot using similar wireless technologies found in home wireless local area networks (WLANs). WISPs are more commonly found in rural environments where DSL or cable services are not available. Wireless Broadband Service work using: An antenna installed outside the house providing either wireless or wired connectivity for devices in the home. ( In many areas, home wireless broadband is competing directly with DSL and cable services. )

1.6 Reliable Networks

Basic characteristics that network architects must address to meet user expectations: Fault tolerance, Scalability, Quality of Service, security A fault-tolerant network is a network that limits the number of affected devices during a failure, it is built to quickly recover when a failure occurs and is dependent on multiple paths between the source and destination of a message. If one path fails the message is sent over a different link this is known as redundancy. Implementing a packet-switched network is one way that reliable networks provide redundancy. A single message, such as an email or a video stream, is broken into multiple message blocks, called packets. Scalability expands a network quickly to support new users and applications, all without degrading the performance of services being accessed by the existing users. Quality of service becomes a primary mechanism for managing congestion and ensuring reliable delivery of content to all users. Congestion occurs when the demand for bandwidth exceeds the amount available. When simultaneous communications are attempted across the network, the demand for network bandwidth can exceed its availability, creating network congestion. Network bandwidth is measured in the number of bits that can be transmitted in a single second, or bits per second (bps). When the volume of traffic is greater than what can be transported across the network, devices will hold the packets in memory until resources become available to transmit them. Two types of network security concerns network administrators must address? a. Network infrastructure security b. Information security Securing the network infrastructure includes: a. physically securing devices that provide network connectivity b. preventing unauthorized access to the management software that resides on them 42. Along with securing the network infrastructure what must network administrators also protect? a. The information contained within the packets being transmitted. b. The information stored on network-attached devices. Three primary requirements to achieve the goals of network security: a. Confidentiality - Data confidentiality means that only the intended and authorized recipients can access and read data. b. Integrity - Data integrity assures users that the information has not been altered in transmission, from origin to destination. c. Availability -.Data availability assures users of timely and reliable access to data services for authorized users.

1.5 Internet Connections

Options available for home use to connect to the internet: a. Cable - Typically offered by cable television service providers, the internet data signal transmits on the same cable that delivers cable television. It provides a high bandwidth, high availability, and an always-on connection to the internet. b. DSL - Digital Subscriber Lines also provides high bandwidth, high availability, and an always-on connection to the internet. DSL runs over a telephone line. In general, small office and home office users connect using Asymmetrical DSL (ADSL), which means that the download speed is faster than the upload speed c. Cellular - Cellular internet access uses a cell phone network to connect. Wherever you can get a cellular signal, you can get cellular internet access. Performance is limited by the capabilities of the phone and the cell tower to which it is connected. d. Satellite - The availability of satellite internet access is a benefit in those areas that would otherwise have no internet connectivity at all. Satellite dishes require a clear line of sight to the satellite. e. Dial Up telephone - An inexpensive option that uses any phone line and a modem. The low bandwidth provided by a dial-up modem connection is not sufficient for large data transfer, although it is useful for mobile access while traveling. Options available for business internet connections: a. Dedicated leased line - Leased lines are reserved circuits within the service provider's network that connect geographically separated offices for private voice and/or data networking. The circuits are rented at a monthly or yearly rate. b. Metro Ethernet - This is sometimes known as Ethernet WAN. In this module, we will refer to it as Metro Ethernet. Metro ethernets extend LAN access technology into the WAN. Ethernet is a LAN technology you will learn about in a later module. c. Business DSL - Business DSL is available in various formats. A popular choice is Symmetric Digital Subscriber Line (SDSL) which is similar to the consumer version of DSL but provides uploads and downloads at the same high speeds. d. Satelite - Satellite service can provide a connection when a wired solution is not available. Traditional separate networks involving data, phones, and television would be separated by many individual network infrastructures for each end device rather than one cable for many devices like today. Converged network: capable of delivering data, voice, and video between many different types of devices over the same network infrastructure. This network infrastructure uses the same set of rules, agreements, and implementation standards. Converged data networks carry multiple services on one network.

1.8 Network Security

Securing a network involves Protocols, technologies, devices, tools, and techniques in order to protect data and mitigate threats. Common external threats to networks: a. Viruses, worms, and Trojan horses - These contain malicious software or code running on a user device. b. Spyware and adware - These are types of software that are installed on the user's device. The software secretly collects information about the user. c. Zero-day attacks - also called zero-hour attacks, these occur on the first day that vulnerability becomes known. d. Threat actor attacks - A malicious person attacks user devices or network resources. e. Denial of service attacks - These slow or crash applications and processes on a network device. f. Data interception and theft - These capture private information from an organization's network. g. Identity theft - This attack steals the login credentials of a user in order to access private data. Most common data breaches happen because of internal users of the network by: a. stolen device b. lost device c. misuse by employees why/how should security be implemented: In multiple layers, using more than one security solution. If one security component fails to identify and protect the network, others may succeed. Basic security components for a home or small office network: a. Antivirus and antispyware - These applications help to protect end devices from becoming infected with malicious software. b. Firewall filtering - Firewall filtering blocks unauthorized access into and out of the network. This may include a host-based firewall system that prevents unauthorized access to the end device, or a basic filtering service on the home router to prevent unauthorized access from the outside world into the network. Network security implementation for a corporate network consists of many components built into the network to monitor and filter traffic: a. Dedicated firewall systems - These provide more advanced firewall capabilities that can filter large amounts of traffic with more granularity. b. Access control lists (ACL) - These further filter access and traffic forwarding based on IP addresses and applications. c. Intrusion prevention systems (IPS) - These identify fast-spreading threats, such as zero-day or zero-hour attacks. d. Virtual private networks (VPN) - These provide secure access into an organization, for remote workers.

1.4 Common Types of Networks

The term internet means "network of networks". It is a collection of interconnected private and public networks. a. Small Home Networks - let you share resources, such as printers, documents, pictures, and music, among a few local end devices. b. Small Office and Home Office Networks - allow people to work from home or a remote office. Self-employed workers use these networks to advertise and sell products, order supplies, and communicate with customers. c. Medium to Large Networks - Used by corporations and schools, can have many locations with hundreds or thousands of interconnected hosts. ( Businesses and large organizations use networks to provide consolidation, storage, and access to information on network servers. Networks provide email, instant messaging, and collaboration among employees. Many organizations use their network's connection to the internet to provide products and services to customers. ) d. World Wide Networks - The internet is a network of networks that connects hundreds of millions of computers worldwide. Network infrastructures vary in Size and area covered, Number of users connected, Number and types of services available, and Area of responsibility Most common types of network infrastructures are: a. Local Area Networks (LANs) - a network infrastructure that provides access to users and end devices in a small geographical area. A LAN is typically used in a department within an enterprise, a home, or a small business network. b. Wide Area Networks (LANs) - a network infrastructure that provides access to other networks over a wide geographical area, which is typically owned and managed by a larger corporation or a telecommunications service provider characteristics of LANs: a. LANs interconnect end devices in a limited area such as a home, school, office building, or campus. b. LAN is usually administered by a single organization or individual. Administrative control is enforced at the network level and governs the security and access control policies. c. LANs provide high-speed bandwidth to internal end devices and intermediary devices, as shown in the figure. characteristics of WANs: a. WANs interconnect LANs over wide geographical areas such as between cities, states, provinces, countries, or continents. b. WANs are usually administered by multiple service providers. c. WANs typically provide slower speed links between LANs The internet is a worldwide collection of interconnected networks ( internetworks, or the internet for short ). Organizations that were developed to help maintain the structure and standardization of internet protocols and processes are: a. Internet Engineering Task Force b. Internet Corporation for Assigned Names and Numbers c. Internet Architecture Board (IAB), plus many others. Intranet is the term used to refer to a private connection of LANS and WANS that belongs to an organization, it is designed to be accessible only by the organization's members, employees, or others with authorization. An Extranet is used by an organization to provide secure and safe access to individuals who work for a different organization but requires access to the organization's data.

1.3 Network Representations and Topologies

a. Network Interface Card (NIC) - A NIC physically connects the end device to the network. b. Physical Port - A connector or outlet on a networking device that the media physically connects to an end device or another networking device c. Interface - Specialized ports on a network device that connect to individual networks. ( Because routers connect networks, the ports on a router are referred to as network interfaces. ) Two types of topology diagrams: a. Physical topology diagrams - illustrate the physical location of intermediary devices and cable installation b. Logical topology diagrams - illustrate devices, ports, and the addressing scheme of the network

1.9 The IT Professional

certification exam at the end of this three semester course is the CCNA

1.2 Network Components

two other names for hosts are end devices, clients The term host refers to all computers that are connected to a network and participate directly in network communications, but specifically devices on the network that are assigned a number for communication. ( Internet Protocol (IP) address: identifies the host and the network it is attached to ) Servers are computers with software that allow them to provide information, like email or web pages, to other end devices on the network. Each service requires separate server software. ( A computer with server software can provide services simultaneously to many different clients. EX: client software = Chrome, Firefox ) peer-to-peer networks might be found In small businesses and homes, many computers function as servers and clients on the network. Whereas large networks may require servers and centralized administration. Advantages of peer-to-peer networking: a. easy setup b. less complex c. lower cost because network devices and dedicated servers may not be required. d. can be used for simple tasks such as transferring files and sharing printers Disadvantages of peer-to-peer networking: a. no centralized administration c. not as secure d. not scalable e. all devices act as both client and servers which can slow their performance An end device is either the source or destination of a message transmitted over the network. The purpose of intermediary devices: a. the devices connect the individual end devices to the network, provide connectivity, and ensure that data flows across the network. ( They can connect multiple individual networks to form an internetwork. ) The functions of intermediary network devices: a. Regenerating and retransmitting communication signals b. Maintain information about what pathways exist through the network and internetwork c. Notify other devices of errors and communication failures d. Direct data along alternate pathways when there is a link failure e. Classify and direct messages according to priorities f. Permit or deny the flow of data, based on security settings Modern networks three main types of media to interconnect devices: a. Metal wires within cables - Data is encoded into electrical impulses. b. Glass or plastic fibers within cables (fiber-optic cable) - Data is encoded into pulses of light c. Wireless transmission - Data is encoded via modulation of specific frequencies of electromagnetic waves. Criteria to consider when choosing network media: a. the maximum distance successfully carrying a signal b. the environment the media is installed c. the amount of data and at what speed must it be transmitted d. the cost of the media and installation