1 / 33

CCNA 2 v3. 1 Module 2

CCNA 2 v3. 1 Module 2. CCNA 2. Module 2 Introduction to Routers. Cisco IOS. Cisco Internetwork Operating System is the software that controls routing and switching functions of internetworking devices Network services provided by Cisco IOS : Basic routing and switching functions

tobil
Download Presentation

CCNA 2 v3. 1 Module 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CCNA 2 v3.1 Module 2

  2. CCNA 2 Module 2 Introduction to Routers

  3. Cisco IOS • Cisco Internetwork Operating System is the software that controls routing and switching functions of internetworking devices • Network services provided by Cisco IOS : • Basic routing and switching functions • Reliable and secure access to networked resources • Network scalability

  4. User Router Interface • Cisco IOS software uses a command-line interface (CLI) • This environment is accessible through several methods. • Console session • Uses a low speed serial connection directly from a computer or terminal to the console connection on the router • No initial configuration necessary

  5. Dialup connection: • Using a modem or null modem connected to the router AUX port. • No initial configuration necessary • Telnet session: • At least one interface must be configured with an IP address, and virtual terminal sessions must be configured for login and passwords.

  6. Router user interface modes • CLI uses a hierarchical structure. • Entry into different modes to accomplish tasks • E.g., To configure a router interface, the user must enter interface configuration mode. • Command executive (EXEC): Validates and executes the entered commands.

  7. IOS software separates the EXEC sessions into two access levels: • User EXEC mode • Privileged EXEC mode (enable) • User EXEC mode (view only) • Limited number of basic monitoring commands • To check and view the router status • Cannot change the configuration of the router • Prompt >

  8. Privileged EXEC mode (enable mode) • Accesses all router commands • Configuration and management • To ensure authorized users access this mode • Configured it to require a password from the user before accessing it & User ID • Provides access to • Global configuration mode and others • Prompt #

  9. Type enable to enter privileged exec mode Type disable to enter privileged exec mode Entering a question mark (?) at the privileged EXEC level will reveal many more command options than those available at the user EXEC level.

  10. IOS Naming Conventions • Platform (Hardware): C1005 • Features: “b”, Appletalk 40 = 40 bit encryption • Format: F = Flash, M = RAM • Compression: Z = Zip compressed

  11. Consideration when selecting a new IOS image • Compatibility with the router flash and RAM memory • i.e., is there enough space • To find this information use show version • router#show version • Displays the amount of available RAM • …cisco 1721 (68380) processor (revision C) with 3584K/512K bytes of memory. • 3584k main memory • 512k shared memory • router#show flash • Displays the amount of flash memory • …15998976 bytes total (10889728 bytes free

  12. Operation of Cisco IOS Software • The startup process of the router normally loads into RAM and executes one of three operating environments/ modes. • ROM monitor • Boot ROM • Cisco IOS • Systems administrator uses the configuration register setting to control the default start up mode for the router

  13. ROM Monitor: • provides low-level functionality and diagnostics • used to • recover from system failures • recover a lost password • Can only be accessed by direct, physical connection through the console port • Prompt: ROMMON> • Boot ROM : • Prompt: Router(boot)> • Offers only limited IOS features • Used for flash image updates • copy tftp flash • copies an IOS image stored on a TFTP server into the flash memory of the router

  14. Cisco IOS • Normal operating mode • Usually stored in Flash but run from RAM • Prompt: router> • show version • Displays • IOS image and version • Configuration register setting • Amount of available RAM • show flash • Displays the amount of flash memory • Used to verify that the system has sufficient memory to load a new Cisco IOS image

  15. Initial startup of Cisco routers If the router cannot find a configuration file, it enters “setup mode”. It is a basic configuration

  16. Startup routines must accomplish 3 things • Make sure that the router hardware is tested and functional. • Find and load the Cisco IOS software • Flash, TFTP Server, ROM • Find and apply the startup configuration fileor enter the setup mode • NVRAM, TFTP Server, Console

  17. Router Startup Sequence • Powers up • Performs a power-on self test (POST) • Executes diagnostics from ROM to check all hardware modules • This verifies basic operation of CPU, memory, network interface ports • Software initialization • The boot field of the configuration register determines the location to be used in loading the IOS. • Flash (0X2102), TFTP Server, ROM • IOS Software is loaded • List of hardware and software is displayed on console screen • If valid configuration file exists • Configuration file from NVRAM is loaded into main memory • start routing processes, supply addresses for interfaces • If no valid configuration file exists • Operating system searches for TFTP server • If no TFTP server the setup dialog is initiated

  18. Setup Mode • Entered only if configuration file cannot be found in NVRAM or TFTP • Permits administrator to enter minimal router configurations • Default answers appear in [ ] • Press Enter to use these defaults • Press Ctrl-C at any time • to terminate the process(setup mode) • all interfaces will be administratively shutdown

  19. Router LED indicators • An interface LED indicates the activity of the corresponding interface. A green OK LED indicates system is initialized correctly

  20. Examining the initial router bootupOutput Output indicates a problem with the “NVRAM”. It could be “Write erased”

  21. Router Output Tells • Bootstrap version • IOS version the router • Router model • Processor • Number of interfaces • Types of interfaces • Amount of NVRAM • Amount of flash memory

  22. Logging into the router

  23. When entering the Privilaged exec mode if the password: prompt is displayed, enter the password that has been set • Password commands to access privileged EXEC mode • Router(config)# Enable password <password> • Not encrypted • Router(config)#Enable secret <password> • Encrypted • Cannot be the same as enable password • Takes precedence over enable password

  24. From the Privileged mode you can enter the “Global Mode” & can configure the following; • Interface • Subinterface • Line • Router • Route-map • To return to the privileged mode type Ctrl Z.

  25. Keyboard help in the router CLI • Typing a question mark (?) displays a handy list of available commands. (user or privileged modes)

  26. “?” can also be used to complete incomplete commands • Eg .. Setting the router clock

  27. The "^" symbol appears at the point in the command string where an incorrect command, keyword, or argument was entered.

  28. Enhanced editing commands “$” sign indicates that the command has scrolled onto the next line.

  29. Router command history The maximum number of commands held is 256.

  30. The show version command • show version command: • IOS version and descriptive information • Bootstrap ROM version • Boot ROM version • Router up time • Last restart method • System image file and location • Router platform • Configuration register setting

More Related