ITEC 275 Computer Networks – Switching, Routing,

and WANs

Week 1Instructor Professor Robert

D’AndreaWinter 2018

Agenda

• Introductions• Review policies, procedures, and expected

outcomes• Learning Activities• Introduce homework problems• Location of Power Point presentationshttp://cs.franklin.edu/~dandrear/itec275/Winter_2018_Network_Presentations/Week_One_Network_ppt or .pptx

Introductions• Professor Robert D’Andrea– Adjunct faculty at Franklin–Winter term, teach ITEC275 and ITEC 400– Cell phone 614.519.5853

• Industry experience in security, systems administration, network administration, software developer, tester, and deployment engineer of software, hardware systems, and documentation.

• Domestic and international work

Introductions• Program Chair Information Technology

Dr. Kemal Aydin– Kemal.aydin@franklin.edu

AdministrationPrinciples of Computer Networks

Top-Down Network Design A systems analysis approach

to enterprise network design (3rd ed.). Indianapolis, IN: Cisco Press. ISBN: 978-1-58720-283-4

AdministrationPrinciples of Computer Networks

ITEC275 serves as an introduction to the function, design, administration, and implementation of computer networks. Topics include network infrastructure, addressing, sub-netting, architecture, protocols, applications, and the OSI networking model.

Administration• Academic integrity– Items on the Web can serve as “inspiration” for

your solutions if:• You understand the solution as if you had written it

yourself.• You cite your source of inspiration

– Not citing your source can get you charged with cheating/plagiarism.

Administration

• Academic integrity– Items on the Web can serve as “inspiration” for

your solutions if:• You understand the solution as if you had written it

yourself.• You cite your source of inspiration

– Not citing your source can get you charged with cheating/plagiarism.

Note: if a homework problem says “research X,” or “investigate Y,” then I’m expecting a citation! Technically, you should cite your textbook on almost every HW assignment.

Administration

• Academic integrity– Other students cannot serve as a source for your

“inspiration!"• The closer you move toward sharing answers with or

soliciting answers from another person (student or not), the more likely it is that you are cheating.

Administration

• Academic integrity– If you have a vague feeling that you wouldn’t want

your instructor to know about what you’re doing… don’t do it.

–When in doubt, ask your instructor.

Administration

Points breakdownPct Type Coun

tEach Total

20%

Homework 10 20 200

15%

Labs 3 50 150

25%

Design Projects 3 100,100,125

325

30%

Midterm/Final Exam

2 150 300

10%

Reflection Paper 1 25 25

1000

Daily/weekly Activities• Daily: Check for announcements in your email.• Before class

1. Read the associated sections from the text books and key points

2. Read and consider the weekly homework problems• After class

1. Complete the homework assignment2. Work on any scheduled lab assignments3. Note significant learning

Course OutcomesUpon successful completion of this course students

will be able to:• Determine an appropriate approach to design a

network based on customer needs and consideration of financial and technological constraints.

• Identify the design considerations and tradeoffs for campus, LAN, WAN, MAN, and data center infrastructure models.

• Select appropriate WAN components used in a standard WAN architecture.

• Compare and contrast routing and addressing schemas and the mechanisms for implementing each one.

Course OutcomesUpon successful completion of this course

students will be able to:• Identify and describe the components and

standards used for implementing telephony into a data network.

• Configure routers and switches using Cisco IOS commands.

• Effectively communicate how a network design plan meets a customer's connectivity needs.

• Know more about the differences in IPv4 and IPv6 addressing.

COMP 204• Map protocols and addressing,

routing, and switching into the appropriate layer of the OSI model.

• Identify the main characteristics of hubs, switches, and routers.

• Outline the features of the following TCP/IP protocols: UDP, TCP, IP.

• Explain the characteristics of virtual LANs (VLANs) and Spanning Tree Protocol (STP) and the advantages they provide.

Cisco Certification Design Associate (CCDA)

The Associate-level certification are typically network design engineers, technicians, or support technicians. They are expected to design basic campus-type networks and be familiar with routing and switching, security, voice and video, wireless connectivity, and IP (both v4 and v6). They often work as part of a team with those who have higher-level Cisco certifications.

Salary: $95,602

Top-Down Verses Bottom-up Network Design

Top-down network design is an iterative process that recognizes a logical model and the physical design that can change as more or less information becomes available.Main goals of structured systems analysis. 1. Represent the user’s needs 2. Make the project manageable, using the latest techniques and tools available.

Bottom-up network design is an unstructured approach to solving a network problem. This type of approach works on small or flat networks. Scalability isn’t a consideration when using this type of network design approach.

Top-Down Network Design• Analyze your customers business goals. Business goals are

the capability to run network applications to meet an organizations business objectives, within the business constraints. These constraints could be limited number of network personnel, budgets, and timeframe.

• Good network design subscribes to the customers requirements to the letter. This would include business and technical goals, requirements for availability, scalability, affordability, manageability, and security needs. Some customers will specify a required level of network performance, referred to as service level.

Top-Down Network Design• When a customer wants a quick fix design, it is referred to as

a bottom-up network design. Associated with this type of design is unexpected scalability, poor performance, and does not meet the customers most important needs.

• Top-down network design is a methodology for designing networks at the upper layers of the OSI model before referring to lower layers (devices, cabling, and switch configurations).

• Top-down network design includes exploring organizational and group structures to find individuals the network is being designed to provide a services and from whom the design should get valuable information to make the design a success.

Top-Down Network Design• Top-down network design is iterative. Initially, it is

important to get the overall view of the customers requirements. Later, after digesting the high abstractions of the design, then focus on the finer details of the design like protocol behavior, scalability requirements, and technology preferences. Top-down network design recognizes that the logical model and the physical design can change as more information becomes available.

• A top-down network design approach enables the designer to obtain “the big picture” initially, and then by drilling down for specific requirements and technical details.

• Top-down network design is a methodology that grew out of structured software programming and structured systems analysis.

Top-Down Network Design• Top-down network design divides the project up into small

logical pieces known as modules. These modules allow large projects to be more manageable and easier to debug.

Top-Down Network DesignTop-Down Design

Top-Down Network DesignModules are split into logical function entities. • The System Development Life Cycle (SDLC) is a top-down

network design approach made up of four major phases and are carried out in a cyclical fashion:

1. Analyze requirements: Interview users and technical personal to gain an understanding of their business and technical goals for new or existing networks.2. Develop the logical design: Logical topology for the new or existing network, security, switching, routing protocols.

Top-Down Network DesignModules are split into logical function entities.

3. Develop the physical design: This phase addresses the specific technologies and products that are realized in the logical design selected.4. Test, optimize, and document the design: Update the documentation that represents the network design, create test scenarios, build a prototype or pilot network, optimize the network design.

Top-Down Network Design• The major phases of the top-down network design repeats

itself. The user and the network monitoring suggest enhancements or the need for new specifications.

Top-Down Network DesignNetwork Design Plan Life Cycle - Plan Design Implement Operate Optimize (PDIOO)• Plan: Identify the network requirements in this phase.• Design: Complete the bulk of the logical and physical

design.• Implement: Implement the building of the proposed network

design.• Operate: Final test the effectiveness of the network design.

This includes monitoring the network and services. • Optimize: This phase is based on actual operations.

Identifying and resolving problems that were encountered.

Top-Down Network DesignNetwork Design Plan Life Cycle - Plan Design Implement Operate Optimize (PDIOO)• Retire: When part or the whole network design no longer

meets the needs of the company and users, this should be an avenue of consideration. This component is not officially part of the life cycle model.

Top-Down Network DesignThe Plan Design Implement Operate Optimize (PDIOO)

network life cycle is one of many types of network life cycles. It is irrelevant which life cycle is used, as long as long as the network design implements a network design that is structured, planned, modularized, and that feedback from the user is used to enhance the new network design.

Top-Down Network DesignNetwork Design Components• Analyzing business goals:

Knowing your customers business goals and constraints. With a thorough understanding of your customers business objectives, you will be able to provide a network design that will meet your customers approval.• Working with your client:

Research the type of business your client is in before meeting with them. Learn all that you can about his or her market, suppliers, services, and competitive advantage.

Top-Down Network DesignNetwork Design Components• Changes in enterprise network:

Internal users are limited for todays network needs. Your customer now has to think about remote entries both domestically, mobile access, and globally. Security is a topic that cannot be underestimated in our current network environment. • Network must make sense:

Business leaders today are more involved with IT decisions than past administrations. Customers want to operate leaner in data center personnel, power usage, and technology for technology’s sake. They also want to know about the option of utilizing the cloud.

Top-Down Network DesignNetwork Design Components• Networks Offer a service:

IT departments are more service oriented than they use to be in the past.– Governance refers to a focus on consistent, cohesive,

policies, and processes that protect an organization from mismanagement and illegal operations of users of IT services.

– Compliance refers to adherence to regulations that protect against fraud and the disclosure of private customer data.

Top-Down Network DesignNetwork Design Components• Need to Support Mobile Users:

Network users expect network performance to be uniform, regardless of where the user or data resides.

Top-Down Network DesignNetwork Design Components• The Importance of Network Security and Resiliency:

Enterprises have to protect themselves from internal, web, and external from more areas than past environments. • Typical Network Design Business Goals: Listed on pages 13

and 14.

Top-Down Network DesignIdentify the scope of the network design project.• Small in scope:

Sales staff might be allowed to access the enterprise network via VPN • Large in scope:

Engineering personal and remote access through the Enterprise Edge

Network designers should request their customers to help them understand the scope of the network design project.

Top-Down Network DesignIdentify the scope of the network design project.

Network design questions:1. Is the design for a single segment2. A set of LANs or WLANs3. A set of WANs or private network4. Remote-access networks5. Entire enterprise network6. A set of MANs

OSI Reference Model• All People Seem To Need Data

Processing• Each layer provides a different

level of abstraction• Each layer has a well-defined

function• Layer boundaries are chosen to

minimize the information flow between layer boundaries

• The number of layers is kept small enough to be feasible

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI – Physical Layer Transmit bits over a

communication channel Bits can be encoded in digital

form (“0” or “1”) or analog (varied voltage) (did you buy your TV converter?)

Does not have any knowledge of data that it transmits

Examples of media: twisted-pair cable coaxial cable fiber optics wireless

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI – Data Link Layer The bits that are send or received in

the Physical Layer are grouped in logical units called frames

The beginning and end of each frame is usually marked by special characters

Examples: Ethernet Token Ring FDDI ISDN

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI – Network Layer Makes it possible to send units of

information (packets) across different network (routing)

Uniform addressing scheme Helps eliminate network

congestion Regulate flow of data Examples:

IP IPX (Novell anyone?)

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI – Transport Layer Ensures reliable delivery of packets Error recovery Multiplexing the network

connection (the use of the network by multiple applications simultaneously)

Examples: TCP UDP SPX (yeah, that Novell thing)

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI – Session Layer Provides enhanced session services Examples:

Telnet session FTP session rlogin session Cookies (web)

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI – Presentation Layer Manages the way data is

represented: Encryption Encoding

Examples: ASCII EBCDIC HTML XML

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI – Application Layer Provides a protocol for a certain

application Examples:

DNS HTTP FTP SMTP TELNET SNMP

Physical

Data Link

Network

Transport

Session

Presentation

Application

OSI versus TCP/IP

Physical

Data Link

Network

Transport

Session

Presentation

Application

Network Access

Internet

Transport

Application

TCP/IP Model Boundaries

Network Access

Internet

Transport

Application

Application address (port)for TCP and UDP

MAC address (NIC)

IP address (host)

Protocol Data Unit (PDU)• Contains information about the source and

destination of a message in the header.

http://en.wikipedia.org/wiki/TCP/IP_model

Evaluate Business ConstraintsCompany Politics

Throughout your discussion with the customer, try to learn who the individuals are that do the authorization, buying process, and fiscal period when buying occurs Be on the alert for:

• Hidden agendas• Turf wars• Biases• Group relations• Individuals within the company that could cause the network

project to fail (engineers or managers)• Number of employees affected by the new design• Customers preference towards the use of certain vendor’s,

Evaluate Business ConstraintsCompany Politics

• Strategic business or IT plan• Customers preference towards the use of certain

protocols • Forbidden technologies• Are there governmental guidelines that need to be

followed• Determine the amount of risk the customer is willing to

tolerate• Determine the group that controls the budget and the

timeframe that the money is distributed.

Evaluate Project Scheduling Review with Customer

• Timeframe for project• Identify due date• Identify the implementation dates• What are the minor and major milestones

Devices - Network TerminologyDomain: A specific part of a networkBandwidth: The amount of data that can be carried across a network in a given period of time.Unicast data: Data meant for a specific deviceBroadcast data: Data meant for all devicesMulticast data: Data that is meant for a specific group of devicesBandwidth domain: All devices that share the same bandwidth (Collision domain)Broadcast domain: All devices that receive each other’s broadcasts and multicasts

Devices - Network TerminologyGovernance: Focuses on consistency, stability in decisions, policies, and processes that protect a company from being mismanaged and involved in illegal activities of users of IT services.Compliance: The agreement to follow regulations that protect against fraud and the privacy of private customer information.Service level is when a customer specifies a required level of network performance (QoS).

Devices - Hubs• Layer 1 device– Also known as repeaters

• Connects multiple devices so that they are logically on one LAN

• Has no intelligence– Sends data received on one port to all other ports– Devices connected receive all data other

connections send– All devices are on one collision and broadcast

domain

Devices - Switches• Layer 2 device• Segregates multiple devices into smaller LANs• Has some intelligence– Reads source and destination MAC addresses and sends

data to the appropriate port based on that– All devices connected to one switch port are in the same

collision domain– Devices connected to individual switch ports are in their

own collision domain– All devices connected to a switch are in the same

broadcast domain

Devices – Multilayer Switches• Does all that a layer 2 does, but adds layer 3 and 4

capabilities• Acts as a router with some functions in hardware

when used for VLAN functions– Groups ports into one or more VLANs that are

configured (using management software) so that they can communicate as if they were attached to the same wire

– VLANs are identified by different IP ranges– Trunk – A port that carries more than one VLAN

between switches

VLANsPhysical LAN vs. Logical VLAN

Devices - Routers• Layer 3 device• Network perimeter device• Has much more intelligence than switches– Reads source and destination logical addresses and

sends data only where it is needed– Transfers data between LANS but blocks

broadcasts– All devices connected to one router port are in the

same collision/broadcast domain

Switching

• Switches learn which devices are connected their ports by examining traffic

IPv4 Addressing• Class A Address

– Provides 16M hosts– Range of addresses: 1.0.0.0 through 126.0.0.0– Mask 255.0.0.0– Restricted addresses 10.0.0.0 – 10.255.255.255

• Class B Address– Provides 65K hosts– Range of addresses: 128.0.0.0 through 191.255.0.0– Mask 255.255.0.0– Restricted addresses 172.16.0.0 – 172.31.255.255

• Class C Address– Provides 254 hosts– Range of addresses: 192.0.0.0 through 223.255.255.0– Mask 255.255.255.0– Restricted addresses 192.168.0.0 – 192.168.255.255

IPv4 Addressing• Class D Address

-Reserved for Multicasting. In multicasting data is not destined for a particular host, that is why there is no need to extract host address from the IP address, and Class D does not have any subnet mask.

-IP address rage from 224.0.0.0 to 239.255.255.255. • Class E AddressThis IP Class is reserved for experimental purposes only for R&D or Study.

-IP addresses ranges from 240.0.0.0 to 255.255.255.254. Like Class D, this class is not equipped with any subnet mask.

Mask Notation• Values

– Network = 1– Host = 0

• Classful example (Class B address)– 128.35.17.25– 255.255.0.0– 11111111.11111111.00000000.00000000

• Subnets – borrow bits– 255.255.128.0– 11111111.11111111.10000000.00000000Classless IP address notation– 128.35.17.25/17 (VLSM/CIDR)

This Week’s Outcomes• Evaluating business goals and constraints• OSI Model• TCP Model • Network Devices• Definitions/Terms• Classes - IPv4 and IPv6 Addresses• Hubs, Switches, and routers• IPv4 Addressing

Software required• Provided CD\resources\software– Visio 2007

• Instructions - InstallingMSVisio2007.pdf• CISCO.vss – Documents\MyShapes

– MIMIC Virtual Lab• MIMIC software installation is NOT required• Virtual Machine

– VMware View Client v4.6 is needed– Download from http://vlab.franklin.edu– System provisioning takes some time – Logins may not work until week 2 or

3• Purchase (If desired)

– Instructions – installvlab.pdf

Current Week

• Read chapters 1 and 2 in Top-Down Network Design

• Follow ITEC275 course web page for assignments

• Submit all homework to drop box

Q & A

• Questions, comments, concerns?