辅导 EIE3333 Sem 1 23/24 Lab 1 – Configuring Basic Switch Settings Using Packet Tracer讲解 回归

EIE3333

Sem 1 23/24

Lab 1 – Configuring Basic Switch Settings Using Packet Tracer

Topology

Addressing Table

Objectives

Part 1: Configure the Network and Verify the Default Switch Configuration

Part 2: Configure Basic Network Device Settings

•     Configure basic switch settings.

•     Configure the PC IP address.

Part 3: Verify and Test Network Connectivity

•     Display device configuration.

•     Test end-to-end connectivity with ping.

•     Test remote management capabilities with Telnet.

•     Save the switch running configuration file.

Part 4: Manage the MAC Address Table

•     Record the MAC address of the host.

•     Determine the MAC addresses that the switch has learned.

•     Set up a static MAC address.

Background / Scenario

Cisco switches can be configured with a special IP address known as switch virtual interface (SVI). The SVI or management address can be used for remote access to the switch to display or configure settings. If the VLAN 1 SVI is assigned an IP address, by default, all ports in VLAN 1 have access to the SVI management IP address.

In this lab, you will build a simple topology using Ethernet LAN cabling and access a Cisco switch using the console and remote access methods. You will examine default switch configurations before configuring basic switch settings. These  basic  switch settings  include  device  name,  interface  description,  local  passwords, message of the day (MOTD) banner, IP addressing, setting up a static MAC address, and demonstrating the use of a management IP address for remote switch management. The topology consists of one switch and one host using only Ethernet and console ports.

Note: The switch  used  is a Cisco Catalyst 2960.  Other switches and Cisco  IOS versions can  be  used. Depending on the model and Cisco IOS version, the commands available and output produced might vary from what is shown in the labs.

Required Resources

•     Cisco Packet Tracer

•     1 Switch (Cisco 2960 with Cisco IOS Release 15.0(2) lanbasek9 image or comparable)

•     1 PC (Windows 7, Vista, or XP with terminal emulation program, such as Tera Term, and Telnet capability)

•     Console cable to configure the Cisco IOS device via the console port

•     Ethernet cable as shown in the topology

Part 1:  Cable the Network and Verify the Default Switch Configuration

In Part 1, you will set up the network topology and verify default switch settings.

Step 1:  Configure the network as shown in the topology in the Packet Tracer.

Connect the console connection as shown in the topology. Do not connect the PC-A to the Ethernet port of the switch at this time. 

Why must you use a console connection to initially configure the switch? Why is it not possible to connect to the switch via Telnet or SSH?

Step 2:   Verify the default switch configuration.

In this step, you will examine the default switch settings, such as current switch configuration, IOS information, interface properties, VLAN information, and flash memory.

You can access all the switch IOS commands in privileged EXEC mode. Access to privileged EXEC mode should be restricted by password protection to prevent unauthorized use because it provides direct access to global configuration mode and commands used to configure operating parameters. You will set passwords later in this lab.

The privileged EXEC mode command set includes those commands contained in user EXEC mode, as well as the configure command through which access to the remaining command modes is gained. Use the enable command to enter privileged EXEC mode.

a.   Assuming the switch had no configuration file stored in nonvolatile random-access memory (NVRAM), you will be at the user EXEC mode prompt on the switch with a prompt of Switch>. Use the enable command to enter privileged EXEC mode.

Switch> enable

Switch#

Notice that the prompt changed in the configuration to reflect privileged EXEC mode.

Verify a clean configuration file with the show running-config privileged EXEC mode command. If a configuration file was previously saved, it must be removed. Depending on switch model and IOS version, your configuration may look slightly different. However, there should be no configured passwords or IP address. If your switch does not have a default configuration, erase and reload the switch.

Note: Appendix A details the steps to initialize and reload the devices.

b.   Examine the current running configuration file.

Switch# show running-config

How many FastEthernet interfaces does a 2960 switch have? ________

How many Gigabit Ethernet interfaces does a 2960 switch have? ________

What is the range of values shown for the vty lines? ________

c.    Examine the startup configuration file in NVRAM.

Switch# show startup-config

startup-config is not present

Why does this message appear? _________________________________________________________

d.   Examine the characteristics of the SVI for VLAN 1.

Switch# show interface vlan1

Is there an IP address assigned to VLAN 1? ________

What is the MAC address of this SVI? Answers will vary. ______________________________________

Is this interface up?

e.   Examine the IP properties of the SVI VLAN 1.

Switch# config terminal

Switch (config)# interface vlan1

Switch (config-if)# no shutdown

Switch (config-if)# exit

Switch (config)# exit

Switch# show ip interface vlan1

What output do you see?

f.    Connect PC-A Ethernet cable to port 6 on the switch and examine the IP properties of the SVI VLAN 1. Allow time for the switch and PC to negotiate duplex and speed parameters.

Note: If you are using Netlab, enable interface F0/6 on S1.

Switch# show ip interface vlan1

What output do you see?

g.   Examine the Cisco IOS version information of the switch.

Switch# show version

h.   Examine the default properties of the FastEthernet interface used by PC-A. Switch# show interface f0/6

i.     Examine the default VLAN settings of the switch.

Switch# show vlan

j.     Examine flash memory.

Issue one of the following commands to examine the contents of the flash directory.

Switch# show flash

Switch# dir flash:

Files have a file extension, such as .bin, at the end of the filename. Directories do not have a file extension.

Part 2:  Configure Basic Network Device Settings

In Part 2, you configure basic settings for the switch and PC.

Step 1:   Configure basic switch settings including hostname, local passwords, MOTD banner, management address, and Telnet access.

In this step, you will configure the PC and basic switch settings, such as hostname and an IP address for the switch management SVI. Assigning an IP address on the switch is only the first step. As the network administrator, you must specify how the switch is managed. Telnet and SSH are the two most common management methods. However, Telnet is not a secure protocol. All information flowing between the two devices is sent in plain text. Passwords and other sensitive information can be easily looked at if captured by a packet sniffer.

a.   Assuming the switch had no configuration file stored in NVRAM, verify you are at privileged EXEC mode. Enter enable if the prompt has changed back to Switch>.

Switch> enable

Switch#

b.   Enter global configuration mode.

Switch# configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Switch(config)#

The prompt changed again to reflect global configuration mode.

c.   Assign the switch hostname.

Switch(config)# hostname S1

S1(config)#

d.   Configure password encryption.

S1(config)# service password-encryption

S1(config)#

e.   Assign class as the secret password for privileged EXEC mode access.

S1(config)# enable secret class

S1(config)#

f.    Prevent unwanted DNS lookups.

S1(config)# no ip domain-lookup

S1(config)#

g.   Configure a MOTD banner.

S1(config)# banner motd #

Enter Text message.  End with the character ‘#’ .

Unauthorized access is strictly prohibited. #

h.   Verify your access settings by moving between modes.

S1(config)# exit

S1#

*Mar  1 00:19:19.490: %SYS-5-CONFIG_I: Configured from console by console

S1# exit

S1 con0 is now available

Press RETURN to get started.

Unauthorized access is strictly prohibited.

S1>

i.     Go back to privileged EXEC mode from user EXEC mode. Enter class as the password when prompted.

S1> enable

Password:

S1#

Note: The password does not display when entering.

j.     Enter global configuration mode to set the SVI IP address of the switch. This allows remote management of the switch.

Before you can manage S1 remotely from PC-A, you must assign the switch an IP address. The default configuration on the switch is to have the management of the switch controlled through VLAN 1.

However, a best practice for basic switch configuration is to change the management VLAN to a VLAN other than VLAN 1.

For management purposes, use VLAN 99. The selection of VLAN 99 is arbitrary and in no way implies that you should always use VLAN 99.

First, create the new VLAN 99 on the switch. Then set the IP address of the switch to 192.168.1.2 with a subnet mask of 255.255.255.0 on the internal virtual interface VLAN 99.

S1# configure terminal

S1(config)# vlan 99

S1(config-vlan)# exit

S1(config)# interface vlan99

%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan99, changed state to down

S1(config-if)# ip address 192.168.1.2 255.255.255.0

S1(config-if)# no shutdown

S1(config-if)# exit

S1(config)#

Notice that the VLAN 99 interface is in the down state even though you entered the no shutdown command. The interface is currently down because no switch ports are assigned to VLAN 99.

k.   Assign all user ports to VLAN 99.

S1 (config)# interface range f0/1 – 24,g0/1 - 2

S1 (config-if-range)# switchport access vlan 99

S1 (config-if-range)# exit

S1 (config)#

%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan99, changed state to up

To establish connectivity between the host and the switch, the ports used by the host must be in the

same VLAN as the switch. Notice in the above output that the VLAN 1 interface goes down because none of the ports are assigned to VLAN 1. After a few seconds, VLAN 99 comes up because at least one active port (F0/6 with PC-A attached) is now assigned to VLAN 99.