CCNA Guide to Cisco Networking Fundamentals Fourth Edition

1. CCNA Guide to Cisco Networking Fundamentals Fourth Edition Chapter 5 Router and IOS Basics

2. Objectives • Describe the benefits of network segmentation with routers • Understand the elements of the Cisco router user interface • Configure the HyperTerminal program to interface with the Cisco router • Describe the various router configuration modes CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

3. Objectives (continued) • Describe the various router passwords • Understand the enhanced editing features of the Cisco IOS • Compare router components to typical PC components CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

4. Benefits of Routing • Routers provide • Packet filtering • Connections between local networks • Traffic control • Wide area network (WAN) connections • Routers operate at the Network layer of the OSI reference model • Because of Network layer addressing, routers can direct packets to both local and remote segments CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

5. Cisco Router User Interface • Cisco Internetwork Operating System (IOS) • Provides a command-line interface (CLI) • Allows network operators to check the status of the router and network administrators to manage and configure the router • You can access a router in several different ways • Console port (also known as the console) • Auxiliary port (AUX) • Virtual terminals (VTY) • Trivial File Transfer Protocol (TFTP) server CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

6. CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

7. CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

8. Connecting via Terminal Programs • When configuring the router through the console or AUX ports • You must first make the physical connection • Then, you can access the router through a terminal program • Steps to configure HyperTerminal: • Open the HyperTerminal application • Click File on the menu bar, and then click New Connection • Enter a name for the connection CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

9. Connecting via Terminal Programs (continued) • Steps to configure HyperTerminal: (continued) • Configure how you will connect to the router via the Connect To dialog box • If you are connecting to the router through the AUX port, you would provide the router phone number here • If connecting to the router through the console port, click the “Connect using” list box and choose the COM port to which the RJ-45 to DB-9 connector is attached • Configure the following settings for the COM port: Bits per second, 9600; Data bits, 8; Parity, None; Stop bits, 1; Flow control, None CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

10. System Configuration Dialog • If the router has not been configured previously, or if the startup file has been erased • The Cisco IOS will prompt you to run the initial configuration dialog after the router boots • The system configuration dialog presents a series of prompts that guide you through the initial configuration for the router CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

11. CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

12. User Interface • The initial prompt consists of two parts: • The host name of the router followed by the greater than symbol (>) • Default:router> • User EXEC mode (or user mode) • When the prompt displayed is the greater than symbol • Network operator can check router status and review several of the router settings CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

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14. User Interface (continued) • The question mark activates context-sensitive Help on the Cisco router • User mode does not allow you to configure the router • To do this, you must go into the privileged EXEC mode • To enter privileged EXEC, you can type the enable command at the user mode prompt • Next, you may be prompted for a password • Greater than symbol (>) changes to a pound sign (#) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

15. User Interface (continued) • You can do a few things at this prompt • Setup: the setup command will cause the router to enter the system configuration dialog • Copy: configurations can be copied from TFTP servers to the router and therefore change the router configuration • Erase: configuration files as well as the entire IOS can be erased CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

16. Configuration Modes • Global configuration mode • Accessed by typing configure terminal at the enable mode prompt • Interface configuration mode • Allows you to configure the Ethernet and serial interfaces on your router • Line configuration mode • Allows you to configure the virtual terminals, console, and AUX lines that let you access the router CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

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18. Configuration Modes (continued) • Typing exit will take you back one level • Typing end or pressing the Ctrl+Z keys will take you all the way back to the enable prompt • Often, you can discover abbreviated commands by simply trying them • The router will show you the point at which you entered an incorrect character CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

19. Configuration Modes (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

20. Plethora of Passwords CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

21. Plethora of Passwords (continued) • Enable Password and Enable Secret Password configuration • You can set both passwords from the global configuration mode prompt • Because it is encrypted, the enable secret password is more secure than the enable password • You can type no enable secret and no enable password at the global configuration mode prompt • To remove the enable secret and enable passwords CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

22. Plethora of Passwords (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

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24. Plethora of Passwords (continued) • Setting Line passwords • Line passwords are the first line of defense against unauthorized intrusion into the router • You can set passwords for each line used to configure the router • Configure the console line password • Enter line configuration mode • You can also configure passwords on the five virtual terminal lines that exist on every router • In much the same way as on the console port CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

25. Plethora of Passwords (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

26. Plethora of Passwords (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

27. Plethora of Passwords (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

28. Enhanced Editing • By default, the router supports enhanced editing features that allow you to modify lengthy commands • The enhanced editing commands let you jump to the beginning or end of a command line • You can also jump forward or back, character by character, or word by word • You can turn off the enhanced editing features by typing terminal no editing at either the user EXEC or the privileged EXEC prompts • You can turn on terminal editing by typing terminal editing CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

29. Enhanced Editing (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

30. Command History • Command history • Allows you to retrieve previously typed commands • You can see up to 10 previously typed commands by typing show history • From either the user EXEC or privileged EXEC mode • To modify the number of commands stored by the router, you can use the terminal command • Up to 256 previous commands • Type terminal history size n CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

31. Configuring Router Identification • Router host name • Default host name is router • To set the router host name, type hostname followed by the name that you want to set • Configure a banner • A banner is a message that you can configure to display each time someone attempts to log in to the router • Enter global configuration mode by typing config t • Then type banner motd, followed by a space and a delimiting character CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

32. Configuring Router Identification (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

33. Configuring Router Identification (continued) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

34. Configuring Router Identification (continued) • Configure an interface description • Use the description command • The interface description helps you remember which network the interface services CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

35. Configuring the Time and Date • Use the clock set command in enable mode to configure the time • You must be in global configuration mode to configure the time zone CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

36. Router Components • This section discusses the hardware elements of the router: • ROM • Flash memory • NVRAM • RAM/DRAM • Interfaces CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

37. ROM • Read-only memory (ROM) • Loads the bootstrap program that initializes the router’s basic hardware components • Not modified during normal operations, but it can be upgraded with special plug-in chips • The content of ROM is maintained even when the router is rebooted • The ROM monitor firmware runs when the router is turned on or rebooted CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

38. Flash Memory • Flash memory • A type of erasable, programmable, read-only memory (EPROM) • Not typically modified during normal operations • However, it can be upgraded or erased when necessary • The content of flash memory is maintained even when the router is rebooted • Flash memory • Contains the working copy of the current Cisco IOS • Is the component that initializes the IOS for normal router operations CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

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40. NVRAM • Nonvolatile random access memory (NVRAM) • A special type of RAM that is not cleared when the router is rebooted • The startup configuration file for the router is stored in NVRAM by default • This is the first file created by the person who sets up the router • The Cisco IOS uses the configuration file in NVRAM during the router boot process CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

41. RAM/DRAM • Random access memory (RAM) • Also known as dynamic random access memory (DRAM) • A volatile hardware component • Its information is not maintained in the event of a router reboot • Changes to the router’s running configuration take place in RAM/DRAM CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

42. RAM/DRAM (continued) • The IOS contains commands to view each of the router’s components • show running-config • show memory • show buffers • show startup-config • Copy running-config startup-config • Abbreviated as Copy run start CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

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44. Interfaces • A router can ship with a variety of configurable interfaces • A common interface is Ethernet0 • Other types of interfaces include: • Token Ring • Basic Rate Interface (BRI) • Asynchronous Transfer Mode (ATM) • Fiber Distributed Data Interface (FDDI) • Channel Interface Processor (CIP) for Systems Network Architecture (SNA) • High-Speed Serial Interface (HSSI) CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

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46. Summary • Cisco routers use the Cisco IOS to provide an interface for network operators and administrators • The first mode entered is user EXEC (router> prompt) and the next mode is privileged EXEC (router# prompt) • In user EXEC, you can accomplish basic tasks • To actually configure the router, privileged EXEC mode must be accessed • The privileged EXEC mode is often called enable mode CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

47. Summary (continued) • The enable, enable secret, and VTY passwords are set during initial configuration if the system configuration dialog is used • When configured, the enable secret password supersedes the enable password • The components of a router include ROM, flash memory, NVRAM, RAM/DRAM, and interfaces • ROM stores a limited version of the Cisco IOS and routines for checking the hardware during system boot CCNA Guide to Cisco Networking Fundamentals, Fourth Edition

48. Summary (continued) • Flash memory stores the Cisco IOS that is loaded by default during system boot • NVRAM stores the startup copy of the router configuration file that is loaded by default during system boot • RAM/DRAM stores the working copy (running configuration) of the router configuration • Interfaces provide connectivity to various types of LANs and WANs CCNA Guide to Cisco Networking Fundamentals, Fourth Edition