Module 2

Switch Configuration

2Switch Configuration

z Identify the major components of a Catalyst switchz Monitor switch activity and status using LED

indicatorsz Examine the switch bootup output using

HyperTerminalz Use the help features of the command line interfacez List the major switch command modes z Verify the default settings of a Catalyst switchz Set an IP address and default gateway for the

switch to allow connection and management over a network

3Switch Configuration

z View the switch settings with a Web browserz Set interfaces for speed and duplex operationz Examine and manage the switch MAC

address tablez Configure port securityz Manage configuration files and IOS imagesz Perform password recovery on a switchz Upgrade the IOS of a switch

4Switch Configuration

Starting the Switch

6Physical startup of the Catalyst switch

z Switches usually have several ports for the purpose of connecting hosts, as well as specialized ports for the purpose of management.

z Switches typically have no power switch to turn them on and off. They simply connect or disconnect from a power source.

7Switch LED indications

z The front panel of a switch has several lights to help monitor system activity and performance. These lights are called light-emitting diodes (LEDs). The front of the switch has the following LEDs: System LED Remote Power Supply (RPS)

LED Port Mode LED Port Status LEDs

8Switch LED indications

z The System LED: shows whether the system is receiving power and functioning correctly.

z The RPS LED: indicates whether or not the remote power supply is in use.

z The Mode LEDs: indicate the current state of the Mode button used to determine how the Port Status LEDs are interpreted. To select or change the port mode, press the Mode button repeatedly until the Mode LEDsindicate the desired mode.

z The Port Status LEDs: meanings depending on the current value of the Mode LED.

9Port LED definitions based on mode LED state

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Verifying port LEDs during switch POST

Once the power cable is connected, the switch initiates a series of tests called the power-on self test (POST). If the System LED is green, then POST was successful. If the System LED is amber, then POST failed. POST failure is considered to be a fatal error.

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Verifying port LEDs during switch POST

z The Port Status LEDs also change during switch POST.

z The Port Status LEDs turn amberfor about 30 seconds as the switch discovers the network topology and searches for loops.

z If the Port Status LEDs turn green, the switch has established a link between the port and a target, such as a computer.

z If the Port Status LEDs turn off, the switch has determined that nothing is plugged into the port.

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Initial bootup output

z The initial bootup output shows information about the switch, details about POST status, and data about the switch hardware.

z After the switch has booted and completed POST, prompts for the System Configuration dialog are presented.

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Examining bootloader Output

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Examining help in the Switch CLI

z The command-line interface (CLI) for Cisco switches is very similar to the CLI for Cisco routers.

z The help command is issued by entering a question mark (?).

z This form of help is called command syntax help, because it provides applicable keywords or arguments based on a partial command.

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Switch command mode

z Switches have several command modesUser EXEC mode Privileged EXEC mode Global configuration modeInterface modeVlan mode

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Show commands in user EXEC mode

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show running-config

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show interface

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show vlan

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show flash

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show version

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Reset all Switch Configurations & Reload

Configuration Switch

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Verifying the Catalyst switch default configuration

z A switch may be given an IP address, for management purposes. This is configured on the virtual interface, vlan 1.

z By default the switch has no IP address.z The switch ports or interfaces are set to auto mode

and all switch ports are in VLAN 1. VLAN 1 is known as the default management VLAN.

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Flash directory content

z The flash directory, by default has a file that contains the IOS image, a file called env_vars, and a sub-directory called html.

z After configuring the switch it may contain a config.text file and a VLAN database.

z The flash directory has no VLAN database file (vlan.dat) and shows no saved configuration file config.text.

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Switch hostname and passwords

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IP Configuration

To allow the switch to be accessible by Telnet and other TCP/IP applications, IP addresses and a default gateway should be set. By default, VLAN 1 is the management VLAN. (more later)In a switch-based network, all internetworking devices should be in the management VLAN. This will allow a single management workstation to access, configure, and manage all the internetworking devices.

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Set port speed and duplex settings

z The Fast Ethernet switch ports default to: auto-speed auto-duplex.

z This allows the interfaces to negotiate these settings. z When a network administrator needs to ensure an interface

has particular speed and duplex values, the values can be set manually.

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http service and port

A web browser can access this service using the IP address and port 80, the default port for http. The HTTP service can be turned on or off, and the port address for the service can be chosen.

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Web Interface

z Intelligent networking devices can provide a web-based interface for configuration and management purposes.

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Managing the MAC address table

z To examine the addresses that a switch has learned, enter the privileged exec command show mac-addresstable.

z If no frames are seen with a previously learned address, the MAC address entry is automatically discarded or aged out after 300 seconds

z To delete MAC table use the privileged exec command: clear mac-address-table dynamic.

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Show mac-address-table

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Configuring static MAC addresses

z The reasons for assigning a permanent MAC address to an interface include: The MAC address will not be aged out automatically by the

switch. A specific server or user workstation must be attached to the

port and the MAC address is known. Security is enhanced.

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Configuration static MAC address

z To set a static MAC address entry for a switch: Switch(config)#mac-address-table static interface FastEthernet vlan

z To remove this entry use the no form of the command

z Eg:mac-address-table static 0010.7a60.1884 interface f0/1 vlan 1

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Port security

z Anyone can plug in a PC or laptop into one of these outlets.

z This is a potential entry point to the network by unauthorized users.

z Switches provide a feature called port security. z It is possible to limit the number of addresses that can be

learned on an interface. z The switch can be configured to take an action if this is

exceeded. Secure MAC addresses can be set statically. z However, securing MAC addresses statically can be a

complex task and prone to error. z To verify port security status the command show port

security is entered.

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Configuration port security

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Configuration port securitySwitch(config-if)#switchport mode accessz Set the interface mode as access; an interface in the default mode

(dynamic desirable) cannot be configured as a secure port.Switch(config-if)# switchport port-securityz Enable port security on the interfaceSwitch(config-if)# switchport port-security maximum valuez (Optional) Set the maximum number of secure MAC addresses for the

interface. The range is 1 to 132; the default is 1.Switch(config-if)# switchport port-security mac-address mac-

addressz (Optional) Enter a static secure MAC address for the interface, repeating

the command as many times as necessary. z You can use this command to enter the maximum number of secure MAC

addresses. If you configure fewer secure MAC addresses than the maximum, the remaining MAC addresses are dynamically learned.

z Note If you enable sticky learning after you enter this command, the secure addresses that were dynamically learned are converted to sticky secure MAC addresses and are added to the running configuration.

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2950 Configuration

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Copying IOS from TFTP Server

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Managing Switch operation system file

z An administrator should document and maintain the operational configuration files for networking devices.

z The most recent running-configuration file should be backed up on a server or disk.

z The IOS should also be backed up to a local server. The IOS can then be reloaded to flash memory if needed.

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2950 password recovery

z Turn the switch off. Turn it back on while holding down the MODE button on the front of the switch at the time that the switch is power on.

z Release the MODE button after the STAT LED goes out Switch:flash_init Switch:load_helper Switch:dir flash: Switch: rename flash:config.text flash:config.old Switch: boot Switch#rename flash:config.old flash:config.text Switch#copy flash:config.text system:running-config

z Change console and enable passwordFor other catalyst series, search for catalyst password recovery on cisco.com)

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Summary

Good luck with this module!

Module 2Switch ConfigurationSwitch ConfigurationSwitch ConfigurationStarting the SwitchPhysical startup of the Catalyst switchSwitch LED indicationsSwitch LED indicationsPort LED definitions based on mode LED stateVerifying port LEDs during switch POSTVerifying port LEDs during switch POSTInitial bootup outputExamining bootloader OutputExamining help in the Switch CLISwitch command modeShow commands in user EXEC modeshow running-configshow interfaceshow vlanshow flashshow versionReset all Switch Configurations & ReloadConfiguration SwitchVerifying the Catalyst switch default configurationFlash directory contentSwitch hostname and passwordsIP ConfigurationSet port speed and duplex settingshttp service and portWeb InterfaceManaging the MAC address tableShow mac-address-tableConfiguring static MAC addressesConfiguration static MAC addressPort securityConfiguration port securityConfiguration port security2950 ConfigurationCopying IOS from TFTP ServerManaging Switch operation system file2950 password recoverySummaryGood luck with this module!