Networking Programming Week 1 Reviewer.docx

**Networking Programming** **Week 1** **Host Roles** - computer on a network is called **host** or end **device.** **Servers** - computers that provide information to end devices : - Email servers - runs email server software. Clients use client software to access email...

**Networking Programming** **Week 1** **Host Roles** - computer on a network is called **host** or end **device.** **Servers** - computers that provide information to end devices : - Email servers - runs email server software. Clients use client software to access email - Web servers -- runs web server software. Clients use browser software to access web pages. - File servers -- stores corporate and user files. The client devices access these files. A cloud with text in the middle Description automatically generated **Peer to peer** - a device be a client and servers are called peer to peer network. - This type of network design is only recommended for very small networks. **Advantages** **Disadvantages** ----------------------------------------------------------------- ------------------------------- Easy to setup No centralized administration Less complex Not as secure Lower cost Not as scalable Used for simple tasks: transferring files and sharing printers. Slower performance  **\ END DEVICES** - This is where a message originates from or where it is received. Data originates with an end device, flows through the network, and arrives at an end device. **INTERMEDIARY NETWORK DEVICES** - Device that interconnects end devices. - Management of data as it flows through a network is also the role of an intermediary device including: - Regenerate and retransmit data signals - Maintain information about what pathways exist in the network. - Notify other devices of errors and communication failures. - Examples : - Switches - Wireless access points - routers - firewalls  **\ ** **Network Media** - Communication across a network is carried through a medium which allows a message to travel from source to destination. **Media Types** **Description** ----------------------------------------------------------- ------------------------------------------------------------------- ----------------------- Metal wires within cables Uses electrical impulses Glass or plastic fibers within cables (fiber-optic cable) Uses pulses of light  Wireless Transmission Uses modulation of specific frequencies of electromagnetic waves. **Network Representations** - **Network Diagrams** are often called **topology diagrams** - These are symbols used to represent devices within the network. - Important terms to know include: - Network Interface Card (NIC) - Physical Port - Interface  **Topology Diagrams** **Physical Topology Diagrams --** Illustrate the physical location of intermediary devices and cable installation. **Logical Topology Diagrams --** illustrate devices, ports, and the addressing scheme of the network. A diagram of a server room Description automatically generated  **Common Types of Networks** **Network of Many Sizes** - Small Home Networks -- connect a few computers to each other and the Internet - Small Office / Home Office -- enables computer within a home or remote office to connect to a corporate network - Medium to Large Networks -- many locations with hundreds or thousands pf interconnected computers - World Wide Networks -- connects hundreds of millions of computers world-wide -- such as the internet. **LANs and WANs** Network infrastructures vary greatly in terms of: - Size of area covered - Number of users connected - Number and types of services available - Area of responsibility **LAN** **WAN** ------------------------------------------------------ ---------------------------------------------------------- Interconnect end devices in a limited area. Interconnect LANs over wide geographical areas Administered by a single organization or individual. Typically administered by one or more service providers. Provide high-speed bandwidth to internal devices Typically provide slower speed links between LANs **THE INTERNET** - is a worldwide collection of interconnected LANs and WANs - LANs are connected to each other using WANs. - WANs may use copper wires, fiber optic cable, and wireless transmissions. - is not owned by any individual or group. But rather being developed by a group to help maintain structure on the internet. These groups are: - **IETF** - **ICANN** - **IAB** **INTRANETS AND EXTRANETS** - I**ntranet** is a private collection of LANs and WANs internal to an organization that is meant to be accessible only to the organization's members or others with authorization - An **Extranet** might be used to provide secure access to their network for individuals who work for a different organization that need access to their data on their network. A diagram of a company Description automatically generated **Internet Connections** **Internet Access Technologies** There are many ways to connect users and organizations to the internet: - Popular services for home users and small offices include broadband cable, broadband digital subscriber line(DSL), wireless WANs, and mobile services. - Organizations need faster connections to support IP phones, video conferencing and data center storage. - Business-class interconnections are usually provided by the service providers (SP) and my include business DSL, leased lines, and Metro Ethernet. **Home and Small Office Internet Connections** **Connection** **Description** ------------------- ------------------------------------------------------------------------------------ Cable High bandwidth, always on, internet offered by cable television service providers. DSL High bandwidth, always on, internet connection that runs over a telephone line. Cellular Uses a cellphone network to connect to the internet. Satellite Major benefit to rural areas without Internet Service Providers(ISP). Dial-up Telephone An inexpensive, low bandwidth option using a modem.  **\ Business Internet Connections** Corporate business connections may require: - higher bandwidth - dedicated connections - managed services **Type of Connection** **Description** ------------------------ ------------------------------------------------------------------------------------------------------------------------------------------- Dedicated Leased Line These are reserved circuits within the service provider's network that connect distant offices with private voice and/or data networking. Ethernet WAN This extends LAN access technology into the WAN DSL Business DSL is available in various formats including Symmetric Digital Subscriber Lines (SDSL). Satellite This can provide a connection when a wired solution is not available. **The Converging Network** - Before converged networks, an organization would have been separately cabled for telephone, video, and data. Each of these networks would use different technologies to carry the signal. - Each of these technologies would use a different set of rules and standards. - Converged data networks carry multiple services on one link including: - data - voice - video - Converged networks can deliver data, voice, and video over the same network infrastructure. The network infrastructure uses the same set of rules and standards.  **Reliable Network** **Network Architecture** - Network Architecture refers to the technologies that support the infrastructure that moves data across the network. - There are four basic characteristics that the underlying architectures need to address to meet user expectations: - Fault Tolerance - Scalability - Quality of Service(QoS) - Security **Fault Tolerance** - A fault tolerance network limits the impact of a failure by limiting the number of affected devices. - Reliable networks provide redundancy by implementing packet switched network: - Packet switching splits traffic into packets that are routed over a network. - Each packet could theoretically take a different path to the destination. - **NOTE:** not possible with circuit-switched networks which establish dedicated circuits.  **\ ** **Scalability** - A scalable network can expand quickly and easily to support new users and applications without impacting the performance of services to existing users. - Network designers follow accepted standards and protocols in order to make the networks scalable. A diagram of a computer network Description automatically generated **Quality of Service** - Voice and live video transmissions require higher expectations for those services being delivered. - Quality of Service(QoS) is the primary mechanism used to ensure reliable delivery of content for all users. - With QoS policy in place, the router can more easily manage the flow of data and voice traffic.  **\ Network Security** - Two types of network security that must be addressed: - **Network infrastructure Security** - Physical security network devices - Preventing unauthorized access to the devices - **Information Security** - Protection of the information or data transmitted over the network - Three goals of network security: - **Confidentiality -** only intended recipients can read the data - **Integrity --** assurance that the data has not be altered with during transmission - **Availability --** assurance of timely and reliable access to data for authorized users A diagram of a network Description automatically generated **\ ** **Network Trends** **Recent Trends** - **BYOD --** means any device with any ownership, used anywhere. Bring Your Own Device. **Online Collaboration --** Collaborate and work with others over the network on joint projects. - **Video Communications -** A powerful tool for communicating with others. - **Cloud Computing** - Cloud computing allows us to store personal files or backup our data on servers over the internet. - Applications can also be accessed using the Cloud - Allows business to deliver to any device anywhere in the world. - Cloud computing is made possible by data centers - Smaller companies that can't afford their own data centers, lease server and storage services from large data center organizations in the Cloud. - **Four types of Clouds:** - [Public Clouds] -- Available to the general public through a pay-per-use model or free. - [Private Clouds] -- Intended for a specific organization or entity such as the government. - [Hybrid Clouds]- Made up of two or more Cloud types. Each part remains a distinctive object, but both are connected using the same architecture. - [Custom Clouds] -- Built to meet the needs of a specific industry, such as healthcare or media. Can be private or public **Technology Trends in the Home** - Smart home technologies like Amazon Echo Hub, Google nest. etc.  A smart speaker with a weather app Description automatically generated **Powerline Networking** - can allow devices to connect to a LAN where data network cables or wireless communications are not a viable option. - is especially useful when wireless access points cannot reach all the devices in the home like adapter, or Wi-Fi extenders etc.  **Wireless Broadband** - More commonly found in rural environments, a Wireless Internet Service Provider(WISP) is an ISP that connects subscribers to designated access points or hotspots. - Uses the same cellular technology used by a smart phone. - An antenna is installed outside the house providing wireless or wired connectivity for devices at home **Network Security** **Security Threats** - Network Security is an integral part of networking regardless of the size of the network - Securing a network involves many protocols, technologies, devices, tools, and techniques in order to secure data and mitigation threats. - Network security that is implemented must take into account the environment while securing the data, but still allowing for quality of serve that is expected of the network. - **Two types of threats:** - **External Threats** - Viruses, worms, and Trojan horses - Spyware and 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 employees - malicious employees **Security Solutions** - Security must be implemented in multiple layers using more than one security solution - Network security components for home or small office network: - Antivirus and spyware - Firewall - Larger networks have additional security requirements - Dedicated firewall system - Access control lists (ACL) - Intrusion prevention systems (IPS) - Virtual private networks (VPN)