Cisco Netacad Routing and Switching v6 PDF

Preview

Summary

Lectures 1 - 3 of Routing & Internetworking....

Description

Cisco NETACAD Routing and Switching v6.0 Chapter 1: Explore the Network — 1.1 Globally Connected: -

-

-

-

Network has no boundary - supports : Learning Communication Work Play Providing Resources in a Network: Networks of many sizes: - Small Home/Office Networks - 2 to 3 diff. comps/printers. File servers, etc. - Medium to Large Networks - 10-15 comps/printers. Web servers, email servers. Etc. Switches & routers. - World wide networks. Client and Servers: - Clients REQUEST and DISPLAY info. - Servers PROVIDE information to other devices on the network. - Client/Server does not have to physically be a large server & small comp. Can be two of the same devices requesting information from each other (P2P) Peer-to-Peer: - Computers can be both server and client at the same time. - Advantages: Easy, low cost to set-up. Little equipment/knowledge. - Disadvantages: Security is not as good, cannot scale to large networks easily. Will have to put routers etc to scale. 1.2 LANs, WANs and the Internet Network Components: End Devices: - Source or destination of a message (computer, mobile device, tablet, smart watch) - End point of the network. Intermediary Network Devices: - Connect multiple individual networks to form an internetwork. - Connect the individual end devices to the network - Ensure data flows across the network - Provide connectivity. - E.g : Switch/Router. Network Media: - Provides pathway for data transmission - Interconnected devices - Copper, Fiber Optic, Wireless, Radio, Bluetooth. Network Representations: Refer to the image. Topology Diagrams: - Physical : Using physical models and how they’re connected. - Logical : Show IPv4/6 addresses / information.

-

-

-

LANs and WANs: Local Area Networks: - Spans across small geographical area - Interconnected end devices. => Router from ISP provider, converted into different signals. Separating LANs to for different uses i.e gaming, sharing files, etc. - Provides high speed bandwidth to internal devices. Wide Area Networks: - Interconnects LAN (multiple LANs connected). - Administrated by multiple service providers. - Provides slower speed links between LANs. Other network types: Campus Area Networks, Metro Area Network.

-

The Internet: - Worldwide connection of interconnected networks - Not owned by any individual or group - Everything is essentially connected, LANs, WANs, MANs, etc. Layered by - Intranet : Company only - only available internally (if setup properly) - Extranet : Suppliers, customers, collaborators - opened up to internal business, i.e logging into UTS to see your results. - The Internet: The world can see everything. Open to the public. -

-

Internet Connections: - Internet Access Technologies: - Internet Service Providers (ISP) - Broadband cable - *Broadband does not necessarily mean high-speed - Broadband Digital Subscriber Line (DSL) - Wireless WANs - Mobile Services - Business DSL - Leased Lines : Company leases lines to give much faster access. - Metro Ethernet - Types of Internet Connections: - Home and small office. - Business. 1.3 The Network as a Platform Converged Networks (Meshed together): - Traditional Seperate Networks: - Each network with its own rules and regulations. I.e network that only did file service, or email, database. Etc. - The Converging Network: - Capable of delivering data, voice and video over the same network infrastructure. - Everything is merged/done over the same medium. No more separate lines.

-

Reliable Networks: - Four basic characteristics of network architecture. - Fault Tolerance : e.g Multiple power supplies, two network cards into a server incase something happens / breaks, etc. - Scalability : Upgrade the network to put more end devices without updating the main infrastructure. - Quality of Service (QoS) : e.g Consistent bandwidth. - Security : Logins, passwords, encryption, physically securing devices. 1.4 The Changing Network Environment:

-

Trends: - Bring your own device (BYOD) : In the past, companies didn’t like employees bringing their own devices. Now it’s okay as it keeps them from having to purchase it/support it, other than pay for the connection (internet). - Online collaboration : Google Docs/Hangouts. Streaming - Video communications : Skype, Discord, Twitch. - Cloud computing : Amazon/Google/Microsoft/Cisco services where you don’t have to store data locally. Information is not stored locally.

-

Networking Technologies for the Home: - Trends: Smart homes - Nest devices, cameras on the outside/inside of the house where you can watch things via the web. - Powerline Networking: Uses existing electrical wiring to connect devices together. - Wireless Broadband: - Wireless internet service provider (WISP) - Wireless broadband service using cellular technology : Allows you to connect using bluetooth tethering to your internet. Network Security: - Security Threats: - Viruses, worms and trojan horses - Spyware and adware - Zero-day/hour attacks - Hacker attacks - DoS attacks - Data interception and theft - Identity theft - Security Solutions: - Antimalware - Firewall filtering - Dedicated firewall systems - Access control lists - Intrusion prevention systems (IPS) - Virtual private networks (VPN) Network Architecture: - Cisco Network Architecture: - Support tech and applications - Ensure connectivity across any combinations of networks. - CCNA : A first step to a networking career.

-

-

Chapter 2 : Configure a Network Operating System — 2.1 IOS Bootcamp -

Explain the purpose of Cisco IOS. Explain how to access a Cisco IOS device for configuration purposes. Explain how to navigate Cisco IOS to configure network devices. Describe the command structure of Cisco IOS Software.

-

Operating systems: - PC OS → users can interact with the computer. - Done via mouse, keyboard and monitor. - Cisco IOS is also an OS - Allows users to interact with Cisco devices. Cisco IOS enables a technician to: - Use a keyboard to run CLI-based network programs. - Use a keyboard to enter text and text-based commands. - View output on a monitor. All Cisco networking devices come with a default (updateable) IOS.

-

-

-

-

-

-

Cisco IOS Access: - Access methods: - Console (i.e your laptop to console device w/ CAT5e - Pull up terminal etc.) - Auxiliar. - Virtual Terminal (Telnet/SSH) - Don’t have to physically go to the device, can be virtually. - Terminal Emulation Programs: - PuTTY - Tera Term - SecureCRT Navigate the IOS: CISCO IOS Modes of Operation (i.e on a router) - Initial configuration: done through console connection - cannot telnet in on first boot up. Need physical access. - Config. Is then done via various CLI command modes. - Console input is usually light blue on the back of a router. Primary Command Modes: - User EXEC Mode - Privileged EXEC mode Configuration Command Modes: - Configure Terminal  command enters the Global Configuration mode. - Sub-configuration modes are accessible from the Privileged EXEC Mode. - Examples are: switch(config-line)# and switch(config-if)# Navigate Between IOS Modes: - Navigation between modes is done via commands. - The enable  command enters the Privileged EXEC mode. - The exit  command exists to the parent command mode.

-

The IOS Command Structure: - Basic IOS Command Structure: - General syntax for a command is the command followed by any appropriate keywords and arguments. - Keyword: Specific parameter defined in the OS. - Argument: Not predefined, a value or variable defined by the user. - IOS Command Syntax: - Provides the pattern or format that must be used when entering a command. - Cisco IOS Command reference is the ULTIMATE SOURCE OF INFO FOR THIS!! - Hotkeys/Shortcuts: - Commands and keywords can be shortened to the min. No. of chars that identify a unique selection. 2.2 Basic Device Configuration

-

Configure hostnames on a Cisco IOS device using the CLI. Use Cisco IOS commands to limit access to device configurations. Use IOS commands to save the running configuration.

-

Host Names: - Device Names: - Hostnames allow devices to be identified by network admins over a network or the internet. Should be descriptive i.e Switch-Floor-1. - Should be displayed in the topology. - Configure Host Names: - IOS hostnames should: - Start with a letter, end with letter / digit. - Contain no spaces - Use only letters, digits or dashes. - Be less than 64 characters in length. - Command to set name on switch: - Switch# configure terminal - Switch(config)# h  ostname Switch-Floor-1 - Switch-Floor-1(config)# Limit Access to Device Configurations: - Secure Device Access: - Secure privileged EXEC and user EXEC access with a password. - Secure virtual terminal lines with a password. - Configure Passwords: - Strong pw/Avoid reusing passwords. - Encrypt Passwords: - Cisco IOS displays passwords in plain text by DEFAULT. - Passwords SHOULD be encrypted. - Banner Messages: - Important part of the legal process in the event that someone is prosecuted for breaking into a device. - Wording that implies a login is welcome or invited is not appropriate - Often used for legal notification because it is displayed to all connected terminals.

-

-

Save Configurations: - Save the running configuration file: - File stored in NVRAM that contains all the commands that will be used upon startup or reboot. - NVRAM does not lose its contents when the device is powered off. - Alter the Running Configuration: - File stored in RAM that reflects the current config, modifying affects the operation of a Cisco device immediately. - RAM loses ALL its content when the device is powered off/restarted. - Capture Configurations to a Text File - Configuration files can also be saved and archived to a text document. - The configuration can then be edited with any text editor and placed back in the device. 2.3 Address Schemes

-

Explain how devices communicate across network media. Configure a host device with an iP address Verify connectivity between two end devices.

-

Ports and Addresses: - Each end device on a network must be configured with an IP address. - You have to be able to access the end devices, i.e a desktop needs an IP address so it can see the other devices on the network. - Enable devices to establish end-to-end communication on the internet. - The structure of an IPv4 address is called dotted decimal notation and is represented by four decimal numbers between 0 and 255. - IPv6 is the most recent version of IP and the replacement for the more common IPv4. Interface and Ports - Network communications depend on interfaces and the cables that connect them. - Different types of network media have different features and benefits. - Ethernet is the most common LAN technology. Copper ethernet, CAT5e, CAT6. - Switch Virtual Interface (SVI) provides a means to remotely manage a switch over a network. Configure IP Addressing: - Manual IP address configuration for end devices: - (Windows) Manually configure an IPV4 address on a windows host: - Open the control panel - Network sharing center - Change adapter settings and choose the adapter - Right click and select properties to display the Local Area Connection properties. - Automatic IP address Configuration for End devices: - DHCP enables automatic IPv4 address configuration for every end device that has DHCP enabled. No extra configuration is needed. - SVI configuration: - Configure a SVI on a switch by using the interface vlan 1  global config command. Vlan 1 is not an actual physical interface but a virtual one.

-

-

-

Verifying Connectivity: - Interface Addressing Verification: - Cisco IOS supports commands to allow IP configuration verification. - I.e ping 192.168.1.1 - End-to-End connectivity test: - The ping command can be used to connect to another device on the network or a website on the internet.

Chapter 3 : Network Protocols and Communications --

-

3.1 Rules of Communication Describe the types of rules that are necessary to successfully communicate.

-

The Rules - If we’re going to communicate, we need to establish common rules on how to communicate.

-

Rule Establish : A group of people get together to establish rules / protocols. - Identified sender and receiver. - Common language and grammar - Speed and timing of delivery established - Confirmation or acknowledgement requirements. Message Encoding: - Process of converting information into another acceptable form. I.e when the information is transmitted to a different medium (e.g from comp to cable), we need to know how that info is going to be encoded and translated. Message Formatting and Encapsulation Message Size Message Timing - Access method - Flow control - Response timeout Message Delivery Options - Unicast - Multicast - Broadcast

-

-

-

-

-

-

-

-

3.2 Network Protocols and Standards Explain why protocols are necessary in communication. Explain the purpose of adhering to a protocol suite. Explain the role of standards organisations in establishing for network interoperability. Explain how the TCP/IP model and the OSI model are used to facilitate standardisation in the communication process. Protocols: Rules that Govern Communications. Network Protocols: - The role of protocols - How the message is formatted and structured - The process by which networking devices share information about pathways with other networks. - How and when error and system messages are passed between devices. - The setup and termination of data transfer sessions. Protocol interaction: - Example: web server and client. See below image.

Protocol Suites: - TCP/IP is an open standard. - TCP/IP is the most common used today. TCP/IP Protocol Suites (https://paf.dias.ac.cy/main/files/cisco_rs_ite/CCNA-R-S_ITN/course/module3/3.2.2.3/3.2.2.3.html): - Some of the protocols from the TCP/IP protocol suite: - DNS (Application Layer) : Translates domain names like google.com to IP addresses. - HTTP (Application Layer) : Rules for exchanging text/graphics/sound/video/media etc - TCP (Transport layer) : Enables reliable communication b/w processes running on separate hosts. - Reliable, acknowledges transmissions that confirm successful delivery. - IP (Internet Layer) : Receive messages segments from transport layer. Package messages into packets. - PPP (Network Access Layer) : Means of encapsulating packets for transmission.

-

TCP/IP Communication Process: 1. The web servers HTML page is the data to be sent. 2. The application protocol HTTP header is added to the front of the HTML data. a. The header contains various information: i. Version of HTML the server is using. ii. Status code indicating it has information for the web client. 3. HTTP application layer protocol delivers the HTML-formatted web page data to the transport layer. a. The transport layer protocol is used to manage the individual conversation between web server and web client. 4. IP information is added to the front of the TCP information. a. IP assigns the appropriate source and destination addresses. (THIS IS KNOWN AS AN IP PACKET). 5. The ethernet protocol adds information to both ends of the IP packet. a. This is known as the data link frame. i. Frame is delivered to the nearest router along the path towards the web client. ii. Router removed the Ethernet information. iii. Router analyses the IP packet, determines the best path for the packet. iv. Router then inserts the packet into a new frame, and sends it to the next neighbouring router towards the destination. v. (EACH ROUTER REMOVES AND ADDS NEW DATA LINK INFORMATION BEFORE FORWARDING THE PACKET). 6. The data is now transported through the internetwork, which consists of media and intermediary devices. 7. The client receives the data link frames that contain the data. a. Each protocol header is processed and then removed in the opposite order that it was added. 8. The web page information is then passed onto the clients web browser software. Visual Understanding + Order it’s encapsulated. ( 5.ETHERNET ( 4.IP ( 3.TCP ( 2.HTTP ( 1.DATA ) ) ) ) )

-

Standard Organisations: e.g TIA/EIA, ISO, etc. Regulate what goes into the protocols/suites. - Open Standards: - Everyone knows what the standards are - Not controlled by any on person - Easy to adopt. - Internet Standards: e.g ISO. - Electronics and Communications Standards Organisations: TIA/EIA.

-

Reference Models

-

Benefits of using a Layered Model: - Everyone knows how its layered/how it’s going to work. The OSI Reference Model: - Provides list of functions - Describes interactions between layers. OSI Model and TCP/IP Model Comparison - Similar: Transport and network layers - Contrast: Relationship between layers.

-

-

-

3.3 Data Transfer in the Network Explain how data encapsulation allows data to be transported across the network. Explain how local hosts access local resources on a network. Data Encapsulation - Message Segmentation - Segmentation - Break communication into pieces. - Multiplexing - Interleaving the pieces (Arrive at diff times and be put back together) -

-

-

Protocol Data Units: - What are PDUs called at each layer? - According to the OSI Model: - 7. Application - Data - 6. Presentation - Data - 5. Session - Data - 4. Transport - Segment - 3. Network - Packet - 2. Data Link - Frame - 1. Physical - Bit Encapsulation and De-encapsulation Process: - Encapsulating Data : Taking it from Application and sending it down to Physical (OSI model). - Adding information along the way from Application to Physical. - By the time it reached Physical it has a full packet ready to be put onto the medium. - The packet is encapsulated and sent. - Encapsulating: - The packet arrives at layer 1. (Physical) and is brought all the way up to layer 7 and is de-encapsulated completely along the way.

Data Access: - Network Addresses: - Source IP Address - Destination IP address (Ipv4/ipv6) - Deliver the IP packet from the original source to the final destination, either on the same network or to a remote network. - Data Link Address - Source data link address - Destination data link address - Deliver the data link frame  from one network interface card (NIC) to another NIC on the same network - Devices on the same network. - Devices on a remove network - Going to need a remote address if not in the same network....