1 © 2003, Cisco Systems, Inc. All rights reserved. CCNA 3 v3.0 Module 6 Switch Configuration Cisco Networking Academy

222 © 2003, Cisco Systems, Inc. All rights reserved. Objectives Starting the switch Configuring the switch

333 © 2003, Cisco Systems, Inc. All rights reserved. Switches A switch is a Layer 2/Layer 3 network device that acts as the concentration point for the connection of workstations, servers, routers, hubs, and other switches. Switches are multi-port bridges. Switches are the current standard technology for Ethernet LANs that utilize a star topology.

444 © 2003, Cisco Systems, Inc. All rights reserved. Switches Switches are dedicated, specialized computers, which contain a central processing unit (CPU), random access memory (RAM), and an operating system. A switch can be managed by connecting to the console port to view and make changes to the configuration.

555 © 2003, Cisco Systems, Inc. All rights reserved. Physical Startup of Catalyst Switches Switches typically have no power switch to turn them on and off. They simply connect or disconnect from a power source.

666 © 2003, Cisco Systems, Inc. All rights reserved. Fixed Configuration and Modular Switches Some switches are fixed configuration: 2900XL, 2950, 3500 and 3550 Fixed configuration switches have a set number of interfaces (FastE or GigE). Other switches are modular: 4000, 5000, 5500 and 6500 Modular switches have a chassis which can hold different modules for different functionality.

777 © 2003, Cisco Systems, Inc. All rights reserved. Fixed Configuration and Modular Switches

888 © 2003, Cisco Systems, Inc. All rights reserved. Switch LED Indicators

999 © 2003, Cisco Systems, Inc. All rights reserved. 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). The System LED indicates the success or failure of POST. The Port Status LEDs turn amber for about 30 seconds as the switch discovers the network topology and searches for loops. –15 seconds “listening” and 15 seconds “learning” To allow the port to go directly to “forwarding” state, use the ‘ spanning-tree portfast ’ command at the interface.

10 © 2003, Cisco Systems, Inc. All rights reserved. Connecting a Switch to a PC Console is in the back of the switch

11 © 2003, Cisco Systems, Inc. All rights reserved. Examining Help in the Switch CLI

12 © 2003, Cisco Systems, Inc. All rights reserved. Show Commands in User EXEC Mode

13 © 2003, Cisco Systems, Inc. All rights reserved. Verifying the Catalyst Switch Default Configuration show running-config show interface show vlan show flash show version dir flash: show vtp counters|domain show mac-address-table

14 © 2003, Cisco Systems, Inc. All rights reserved. Configuring the Catalyst Switch To overwrite any existing configuration, follow these steps: –Remove any existing VLAN information by deleting the VLAN database file, vlan.dat from the Flash memory directory. –Make sure the switch is not connected to any other switches. –Erase the backup configuration file startup-config. –Reload the switch.

15 © 2003, Cisco Systems, Inc. All rights reserved. Configuring the Catalyst Switch Web Management Interface

16 © 2003, Cisco Systems, Inc. All rights reserved. Managing the MAC Address Table Switches learn the MAC addresses of PCs or workstations that are connected to their switch ports by examining the source address of frames that are received on that port.

17 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Static MAC Addresses Using static MAC address entries increases security … and administration.

18 © 2003, Cisco Systems, Inc. All rights reserved. Configuring Port Security Another option for increased security is to configure port security by limiting the maximum number of MAC addresses allowed on that port to one and shutting down the port if another MAC address is learned.

19 © 2003, Cisco Systems, Inc. All rights reserved. Executing Adds, Moves, and Changes

20 © 2003, Cisco Systems, Inc. All rights reserved. Managing Switch Operation An administrator should document and maintain the operational configuration files for networking devices. The most recent running-configuration file should be backed up on a server or disk. The Cisco IOS Software should also be backed up to a local server. The Cisco IOS Software can then be reloaded to Flash memory if needed.

21 © 2003, Cisco Systems, Inc. All rights reserved. Passwords For security and management purposes, passwords must be set on the console and vty lines. An enable password and an enable secret password must also be set.

22 © 2003, Cisco Systems, Inc. All rights reserved. Firmware and IOS Images IOS and firmware images are periodically released with bugs fixed, new features introduced, and performance improved. If the network can be made more secure, or can operate more efficiently with a new version of the IOS, then the IOS should be upgraded