Networking Basics (Networking Today)

WAN (Wide Area Network)

A WAN is a network infrastructure that spans a wide geographical area Are typically managed by service providers (SPs) or Internet Service Providers (ISPs)

Network Security

Network security must consider the environment, as well as the tools and requirements of the network. It must be able to secure data while still allowing for the quality of service that users expect of the network.

What are the functions of intermediary devices?

1. All intermediary devices Regenerate and retransmit communication signals 2. Maintain information about what pathways exist through the network and internetwork 3. Notify other devices of errors and communication failures 4. Direct data along alternate pathways when there is a link failure 5. Classify and direct messages according to priorities 6. Permit or deny the flow of data, based on security settings Intermediary devices perform some or all of the above functions

What are the advantages of Peer-to-Peer Network

1. Easy to setup 2. Less complex 3. Lower cost because network devices and dedicated servers may not be required 4. Can be used for simple tasks such as transferring files and sharing printers

What are the two type of network security concerns?

1. Network infrastructure security : includes physically securing devices that provide network connectivity and preventing unauthorized access to the management software that resides on them, as shown in the figure. 2. Information Security Network administrators must also protect the information contained within the packets being transmitted over the network, and the information stored on network attached devices. CIA Triad are the requirements of network security

List the functions of intermediary devices.

1. Regenerate and retransmit data signals; 2. Maintain information about what pathways exist through the network and internetwork; 3. Notify other devices of errors and communication failures; 4. Direct data along alternate pathways when there is a link failure; 5. Classify and direct messages according to QoS priorities; 6. Permit or deny the flow of data, based on security settings.

Physical Port

A connector or outlet on a networking device where the media connects to an end device or another networking device

Fault Tolerance (Fault Tolerant Network)

A fault tolerant network is one that limits the number of affected devices during a failure. is built to allow quick recovery when such a failure occurs. depend on multiple paths between the source and destination of a message. If one path fails, the messages are instantly sent over a different link. Having multiple paths to a destination is known as redundancy.

Extranet

A private network that links a company with its suppliers and customers Picture illustrates who has access to the Internet, Extranets, and Intranets Examples: 1. A company that is providing access to outside suppliers and contractors 2. A hospital that is providing a booking system to doctors so they can make appointments for their patients 3. A local office of education that is providing budget and personnel information to the schools in its district

Scalability

A scalable network expands quickly to support new users and applications. When adding new users it does not degrade the performance of the services that are being accessed by existing users networks are scalable because the designers follow accepted standards and protocols. -- because of the standards this allows software and hardware vendors focus on improving products and services without having to design a new set of rules for operating within the network

Hosts

Are all computers that are connected to a network and participate directly in network communication Hosts can be called end devices Some hosts are also called clients the term hosts specifically refers to devices on the network that are assigned an IP address for communication purposes.

Intermediary devices

Are devices that connect individual end devices to the network. They can also connect multiple individual networks to form an internetwork Intermediary devices provide connectivity and ensure that data flows across the network

How do corporate connection options differ from home user options?

Businesses may require high bandwidth, dedicated bandwidth, and managed services. Connection options that are available differ depending on the type of service providers located nearby

CIA (Network Security Requirements)

Confidentiality -Data confidentiality means that only the intended and authorized recipients can access and read data. Integrity - Data integrity assures users that the information has not been altered in transmission, from origin to destination. Availability - Data availability assures users of timely and reliable access to data services for authorized users.

Traditional Separate Networks

Consider a school built thirty years ago. Back then, some classrooms were cabled for the data network, telephone network, and video network for televisions. These separate networks could not communicate with each other. Each network used different technologies to carry the communication signal. Each network had its own set of rules and standards to ensure successful communication. Multiple services ran on multiple networks.

Glass or plastic fibers within cables (fiber-optic cable)

Data is encoded into pulses of light

Wireless transmission

Data is encoded via modulation of specific frequencies of electromagnetic waves

What are some common methods that businesses use to connect to the Internet in your area?

Dedicated leased line, Metro-E, DSL, Cable, Satellite

Logical Topology Diagrams

Identify devices, ports, and addressing scheme. You can see which end devices are connected to which intermediary devices and what media is being used

Physical Topology Diagrams

Identify the physical location of intermediary devices, and cable installation. You can see the rooms in which these devices are located are labeled in this physical topology.

In Packet Tracer, only the Server-PT device can act as a server. Desktop or Laptop PCs cannot act as a server. Based on your studies so far, explain the client-server model.

In modern networks, a host can act as a client, a server, or both. Software installed on the host determines the role it plays on the network. Servers are hosts that have software installed that enables them to provide information and services, like email or web pages, to other hosts on the network. Clients are hosts that have software installed that enables them to request and display the information obtained from the server. A client could also be configured as a server simply by installing server software.

What is a Peer-to-Peer Network

Is a network where many computers function as the servers and clients on the network.

Explain the difference between a LAN and a WAN. Give examples of each.

LANs provide access to end users in a small geographical area. A home office or school campus are examples of LANs. WANs provide access to users in a wide geographical area over long distances spanning a few miles to thousands of miles. A Metropolitan Area Network and the Internet are examples of WANs. A company's intranet may also connect multiple remote sites using a WAN.

Cloud Types

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. 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. 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. Community clouds - A community cloud is created for exclusive use by specific entities or organizations. The differences between public clouds and community clouds are the functional needs that have been customized for the community. For example, healthcare organizations must remain compliant with policies and laws (e.g., HIPAA) that require special 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.

Security Solutions SOHO

Security should be implemented in multiple layers, for redundancy. -- both for home and business ISPs sometimes will have some contracted security measures in place Antivirus and antispyware - These applications help to protect end devices from becoming infected with malicious software. 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.

Interface

Specialized ports on a networking device that connect to individual networks Because routers connect networks, the ports on a router are referred to as network interfaces.

Converged Networks

Today, the separate data, telephone, and video networks converge. Unlike dedicated networks, converged networks are 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.

Security Solutions Corporate Networks

Usually a corporation will have components built into the network to monitor and filter outside traffic Other security requirements: Dedicated firewall systems - These provide more advanced firewall capabilities that can filter large amounts of traffic with more granularity. Access control lists (ACL) - These further filter access and traffic forwarding based on IP addresses and applications. Intrusion prevention systems (IPS) - These identify fast-spreading threats, such as zero-day or zero-hour attacks. Virtual private networks (VPN) - These provide secure access into an organization for remote workers.

What are some common external threats to networks?

Viruses, worms, and Trojan horses - These contain malicious software or code running on a user device. Spyware and adware - These are types of software which are installed on a user's device. The software then secretly collects information about the user. Zero-day attacks - Also called zero-hour attacks, these occur on the first day that a vulnerability becomes known. Threat actor attacks - A malicious person attacks user devices or network resources. Denial of service attacks - These attacks slow or crash applications and processes on a network device. Data interception and theft - This attack captures private information from an organization's network. Identity theft - This attack steals the login credentials of a user in order to access private data.

LAN (Local Area Network)

is a network infrastructure that spans a small geographical area A network serving a home, small building, or a small campus is considered a LAN

Intranet

is a term often used to refer to a private connection of LANs and WANs that belongs to an organization Designed to be accessible only by the organization's members, employees, or others with authorization.

Internet

is a worldwide collection of interconnected networks AKA internetworks -- internet for short You can view inet as a collection of interconnected LANs and WANs -- in picture

What are some of the common ways a home user connects to the Internet?

Cable, DSL, dial-up, cellular, and satellite.

small office/home office (SOHO) networks

-allow people to work from home, or a remote office. -many computers function as both servers and clients on the network (Peer-to-Peer Network) Self employed workings use these types of networks to advertise and sell products, order supplies, and communicate with customers

World Wide Networks

The Internet is a network of networks that connects hundreds of millions of computers world-wide.

Quality of Service (QoS)

When simultaneous communications are attempted across the network, the demand for network bandwidth can exceed its availability, creating network congestion. The focus of QoS is to prioritize time-sensitive traffic. The type of traffic, not the content of the traffic, is what is important. I.E: With a QoS policy in place, the router can manage the flow of data and voice traffic, giving priority to voice communications if the network experiences congestion.

How do network infrastructures vary?

1. Size of the area covered 2. Number of users connected 3. Number and types of services available 3. Area of responsibility

Metal wires within cables

Data is encoded into eletrical impulses

NIC

A NIC physically connects the end device to the network

In the Packet Tracer network, how many WANs do you see? How many LANs do you see? The Internet in this Packet Tracer network is overly simplified and does not represent the structure and form of the real Internet. Briefly describe the Internet.

There are two: the Internet and the Intranet WANs. There are three LANs, easily identifiable because each has a border and label. The Internet is mostly used when we need to communicate with a resource on another network. The Internet is a global mesh of interconnected networks (internetworks).

Small Home Networks

connect a few computers to each other and to the internet

Packet Switched Network

is one way that reliable networks provide redundancy Packet switching splits traffic into packets that are routed over a shared network. A single message, such as an email or a video stream, is broken into multiple message blocks, called packets. Each packet has the necessary addressing information of the source and destination of the message. The routers within the network switch the packets based on the condition of the network at that moment. With this type of network each packet could take a very different path to its destination

Powerline Networking

the connection of devices to the Internet through the use of existing electrical wiring See picture for visual

End Devices

Are either the source or destination of a message transmitted over a network. Every end device on a network has an address - it uses the address of the destination end device to specify where to deliver the message.

What are 4 Important networking trends that affect organizations and consumers?

1. Bring Your Own Device (BYOD) BYOD enables end users the freedom to use personal tools to access information and communicate across a business or campus network. BYOD means any device, with any ownership, used anywhere. 2. Online collaboration Collaboration is defined as "the act of working with another or others on a joint project." 3. Video communications Video is becoming a critical requirement for effective collaboration as organizations extend across geographic and cultural boundaries. 4. Cloud Computing For security, reliability, and fault tolerance, cloud providers often store data in distributed data centers. Instead of storing all the data of a person or an organization in one data center, it is stored in multiple data centers in different locations. For businesses, Cloud computing extends the capabilities of IT without requiring investment in new infrastructure, training new personnel, or licensing new software. These services are available on-demand and delivered economically to any device that is anywhere in the world without compromising security or function.

What are four basic characteristic that network architects must address to meet user expectations

1. Fault Tolerance 2. Scalability 3. Quality of Service (QoS) 4. Security

What are the specific characteristics of a LAN network

1. LANs interconnect end devices in a limited area such as a home, school, office building, or campus. 2. A 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. 3. LANs provide high-speed bandwidth to internal end devices and intermediary devices, as shown in the figure.

What are the Disadvantages of Peer-to-Peer Network

1. No centralized administration 2. Not as secure 3. Not scalable 4. All devices may act as both clients and servers which can slow their performance

List the criteria for choosing a network media type.

1. The distance the media can successfully carry a signal. 2. The environment in which the media is to be installed. 3. The amount of data and the speed at which it must be transmitted. 4. The cost of the media and installation.

What are the specific characteristics of a WAN network

1. WANs interconnect LANs over wide geographical areas such as between cities, states, provinces, countries, or continents. 2. WANs are usually administered by multiple service providers. 3. WANs typically provide slower speed links between LANs. Picture shows a WAN that interconnects two LANs

Which of the following is the name for all computers connected to a network that participate directly in network communication? A: servers B: intermediary devices C: hosts D: Media

C: hosts

What are some Home and Small Office Internet Connections

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. DSL - Digital Subscriber Lines also provide 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. 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. 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. 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.

Types of Business Internet Connections

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. 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. 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. Satellite - Satellite service can provide a connection when a wired solution is not available.

Wireless Broadband

Wireless Internet Service Provider (WISP) is an ISP that connects subscribers to a designated access point or hot spot using similar wireless technologies found in home wireless local area networks (WLANs). Typically in rural areas where DSL or cable services are not available An antenna is 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.

What do home users, remote workers, and small offices use to connect to the internet

They typically use ISPs

Network Security Internal Threats

There have been many studies that show that the most common data breaches happen because of internal users of the network. This can be attributed to lost or stolen devices, accidental misuse by employees, and in the business environment, even malicious employees. BYOD is making corporate data more vulnerable When developing a security policy it is important to address both internal and external security threats SEE FIGURE

Small Office and Home Office Networks

allows computers in a home office or a remote office to connect to a corporate network, or access centralized, shared resources

Medium to Large Networks

used by corporations and schools, can have many locations with hundreds or thousands of interconnected hosts