ICND I 100 101 07 Installing Operating Cisco LAN Switches Pptx

8/10/2019 ICND I 100 101 07 Installing Operating Cisco LAN Switches Pptx

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By Muhammad Asghar Khan

[email protected]

07 - Installing & Operating Cisco LAN

Switches

Reference: Cisco CCENT/CCNA ICND1 100-101 Official Cert Guide By WENDELL ODOM

Cisco Press


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Agenda

www.asghars.blogspot.com

Introduction

Cisco Catalyst Switch BrandCisco Linksys Switch Brand

The Cisco Catalyst 2960 Switch

Switch Status from LEDs

Accessing the Cisco IOS CLI

CLI Access from the Console

CLI Access with Telnet & SSH

Setting Password Security for CLI

Cisco IOS Modes of Operation

User EXEC Mode

Privileged EXEC Mode

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Agenda


Global Configuration Mode

Switch Configuration FilesTypes of Switch Memory

RAM/DRAM

ROM

Flash MemoryNVRAM

Types of Configurations

Initial Configuration (Setup Mode)

Startup Configuration

Running Configuration

Copying Configuration Files

Erasing Configuration Files

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Introduction


Cisco has two major brands of LAN switching products

Cisco Catalyst Switch Brand

Includes a large collection of switches, all of which havebeen designed with Enterprises in mind

The Catalyst switches have a wide range of sizes, functions,

and forwarding rates

Cisco Linksys Switch Brand

Includes a variety of switches designed for use in the home

The CCNA exams focus on how to implement LANsusing Cisco Catalyst switches

Both the Catalyst and Linksys brands of Cisco switchesprovide the same base features

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Introduction


Within the Cisco Catalyst brand, Cisco produces a wide

variety of switch series or families

Each switch series includes several specific models ofswitches that have:

Similar Features,Similar Price-Versus-Performance trade-offs, and

Similar Internal components

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Cisco positions the 2960 series/family of switches as

full-featured, low cost wiring closet/cabinet switchesfor enterprises

2960 switches are mostly used as access switches

The distribution layer switches are often from adifferent Cisco switch family, typically a more powerfuland more expensive product family

Figure on next slide shows the photo of the 2960switch series from Cisco; each switch is a differentspecific model of switch inside the 2960 series

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Cisco Catalyst 2960 Series

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Three of the five switches have 48 RJ-45 10/100 ports, meaning

that these ports can negotiate the use of 10BASE-T or100BASE-TX Ethernet

These switches also have few additional RJ-45 ports on theright that are 10/100/1000 interfaces on the right, intended to

connect to the core switches of an Enterprise campus LANCisco refers to a switchs physical connectors as either

interfaces or ports. Each interface has a number in the stylex/y, where x and y are two different numbers

In a 2960, the number before the / is always 0. The first10/100 interface on a 2960 is numbered starting at 0/1, thesecond is 0/2, and so on

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The interfaces also have names; for example, interface

FastEthernet 0/1 is the first of the 10/100 interfaces Any Gigabit-capable interfaces would be called

GigabitEthernet interfaces

Cisco supports two major types of switch operating systems:

Internetwork Operating System (IOS)Catalyst Operating System (Cat OS)

Most Cisco Catalyst switch series today run only Cisco IOS

But for some historical reasons, some of the high-end Cisco LANswitches support both Cisco IOS and Cat OS

Cisco also uses the term hybrid to refer to 6500 switches thatuse Cat OS and the term native to refer to 6500 switches thatuse Cisco IOS

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Switch Status from LEDs

Switch hardware includes several LEDs that provide somestatus and troubleshooting information

Figure shows the front of a 2960 series switch, with five

LEDs on the left, one LED over each port, and a modebutton

SYST (System)

RPS (Redundant Power Supply)

STAT (Status)DUPLX (Duplex)

SPEED

Port

MODE

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To make sense of the LEDs, consider the specific example of

SYST LED SYST LED provides a quick overall status of the switch, with three

states on most 2960 switch models:

Off:switch is not powered on

On (green): switch is powered on and operational (Cisco IOS hasbeen loaded)

On (amber): switchs Power-On Self Test (POST) process failed, andthe Cisco IOS did not load. In this case, the typical response is topower the switch off and back on again. If the same failure occurs,a call to the Cisco Technical Assistance Center (TAC) is typically the

next stepThe particular details of how each LED works differ between

different Cisco switch families and with different models insidethe same switch family

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The port LEDsthe LEDs sitting above or below each

Ethernet portmeans something different depending onwhich of three port LED modes is currently used on theswitch

The switches have a mode button (labeled with number 6

in Figure) that, when pressed, cycles the port LEDsthrough three modes:

STAT

DUPLX, andSPEED

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Each of the three port LED modes changes the meaning

of the port LEDs associated with each port In STAT (status) Mode

Off: The link is not working

Solid Green: The link is working, but theres no current traffic

Flashing Green: The link is working, and traffic is currentlypassing over the interface

Flashing Amber: The interface is administratively disabled orhas been dynamically disabled for a variety of reasons

In SPEED ModeDark LED; meaning 10 Mbps

Solid Green Light; meaning 100 Mbps

Flashing Green; meaning 1000 Mbps (1 Gbps)

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The command-line interface (CLI) is a text-based interface in

which the user, typically a network engineer, enters a textcommand and presses Enter

Pressing Enter sends the command to the switch, whichtells the device to do something

Cisco IOS not also define an interface (CLI) for humans but italso controls the switchs performance and behavior

The switch CLI can be accessed through three popular

methodsthe console, Telnet, and Secure Shell (SSH)

The console is a physical port built specifically to allowaccess to the CLI

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Telnet and SSH use the IP network in which the switchresides to reach the switch

Figure on next slide shows the cabling

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Next, a terminal emulator software package (e.g. tera

term) must be installed and configured to use the PCsserial port, matching the switchs console port settings

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Telnet or SSH application protocol calls the terminal

emulator a Telnet Client or SSH Client and device thatlistens for commands is called Telnet Server or SSHServer

The switch runs Telnet and SSH server software by

default, but needs to have an IP address configuredTelnet & SHH is TCP based where Telnet uses the port 23

and SHH uses the port 22

The key difference b/w Telnet & SHH is that Telnet sends

all data as clear-text data, while the SHH sends data inmore secure manner by using the encryption

By default switch allows only console access, but noTelnet or SHH access

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Cisco switches refers to console as console line-specifically,console line 0

Cisco switches also support 16 Telnet sessions, referenced asvirtual terminal (vty) lines 0 through 15

SSH requires a little more effort than console & Telnet, as SSHuses public key cryptography to exchange a shared session key

Additionally, SSH requires both username and password forlogin

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Cisco IOS provides access to several different command

modesEach command mode provides a different group of

related commands

Entering a question mark(?) at the system promptallows you to obtain a list of commands available foreach command mode

The three basic modes are:

User EXEC ModePrivileged EXEC Mode

Global Configuration Mode

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Privileged EXEC Mode

Privileged EXEC commands set operating parametersPrivileged EXEC mode is password protected

It is also called simply privileged or enable mode

To enter privileged mode, enter the enableEXEC commandfrom user EXEC mode:

To set enable mode password, use either the enablepasswordor enable secretcommands

It is recommended that you use the enable secretcommandbecause it uses an improved encryption algorithm

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Use the enable passwordcommand only if you boot an older

image of the Cisco IOS softwareFigure shows the User & Privileged modes

Global Configuration ModeGlobal configuration commands apply to features that affect

the system as a whole, rather than just one protocol orinterface

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Commands entered in configuration mode update the

active configuration fileConfiguration mode itself contains submodes

Submodes used to configure specific system features

Context-setting commands move you from oneconfiguration mode or context to another

To enter global configuration mode, enterthe configure command from privileged EXEC mode:

The system prompt changes to indicate that you are nowin global configuration mode

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Some of the sub-modes are:

Access-list Configuration

Line Configuration

Interface Configuration

Access-list ConfigurationUse access-list configuration mode when you are creating a

named IP or IPX access list

From global configuration mode, use the ip access-list

or ipx access-list command

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Line configuration

Line configuration commands modify the operation of anauxiliary, console, physical, or virtual terminal line

From global configuration mode, enter by specifying a linewith a line {aux|con|tty|vty} line-number [ending-line-number]

command

Interface Configuration

The commands entered in this mode modify the operation ofan interface

From global configuration mode, enter by specifying aninterface with an interfacecommand

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Figure shows the relationship b/w EXEC modes and

configuration mode

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The endor Ctrl+z key sequence exit the user from any

part of configuration mode and go back to privilegedEXEC mode

While the exitcommand backs you out of configuration

mode one sub-configuration mode at a time

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Switch Configuration Files


To work with files, you need some sort of memory

Cisco switches uses several types of permanent memory as:RAM/DRAM

Used by switch as it is used by any other computer

ROM

Stores bootstrap/boot-helper program, that is loaded when theswitch first power on

Bootstrap program finds the image of IOS and load it into theRAM

Flash Memory

Found in the form of chip inside the switch or a removablememory card

Stores the Cisco IOS images and it is the default location wherebootstrap searches for the IOS image

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It can also be used to store configuration or backup files

Nonvolatile RAM (NVRAM)Stores the initial or startup configuration file

A configuration file saves the switch configurationcommands in text format

Switch maintains the following types of configuration:

Initial Configuration (Setup Mode)

Setup mode leads a switch administrator to a basic switch

configuration by using questions that prompt for basicswitch configuration parameters

Figure on next slide describe the process used by setupmode

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Startup ConfigurationUsed for initialization when the switch boots

If this file does not exist, the system boots using the factorydefaults

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It is stored in NVRAM

You can use the show startup-config command to view thestartup configuration file

The IOS File System (IFS) refers to startup-config asnvram:startup-config

Running ConfigurationStores the currently used configuration commands

This file changes dynamically when someone enterscommands in configuration mode

It is stored in RAM If the switch is reloaded (rebooted) and the running

configuration is not saved all commands will be lost

You can use the show running-config command to view the

startup configuration file

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The IOS File System (IFS)

refers to running-config

as system:running-config

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Copying Configuration Files

The copy command can be used to copy files b/w RAMor NVRAM on a switch and a TFTP server

The copy command can be summarized as:

copy { tftp|running-config|startup-config }

{ tftp|running-config|startup-config }

It always replaces the existing configuration file when thefile is copied into NVRAM or into a TFTP server, while itmerged the configuration file into the running-config filein RAM

Figure on next slide depicts the locations and results ofcopy operation

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Erasing Configuration Files

You can use three different commands to erase thecontents of NVRAM

write erase (older)

erase startup-config (older)

erase nvram (recomened)

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All the three commands will erase the contents of the

NVRAM configuration fileNote there is no command to erase the contents of the

running-config file; to clear the running-config file, simplyerase the startup-config file and then reloadthe

switch

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Documents

ICND I 100 101 07 Installing Operating Cisco LAN Switches Pptx