© 2004 Cisco Systems, Inc. All rights reserved. Operating and Configuring Cisco IOS Devices Configuring a Router INTRO v2.0—8-1

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-2 Outline Overview Router Configuration Modes Configuring a Router from the Command Line Configuring Router Interfaces Configuring the Router IP Address Verifying the Interface Configuration Summary Lab Exercise 8-3: router Start-up and Initial Configuration Lab Exercise 8-4: Using the Router CLI Lab Exercise 8-5: Operating and Configuring a Cisco IOS Device

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-3 Overview of Router Modes

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-4 Saving Configurations Copies the current configuration to NVRAM

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-5 Sets the local identity or message for the accessed router or interface Configuring Router Identification

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-6 Configuring a Router Password

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-7 Other Console-Line Commands Router(config)#line console 0 Router(config-line)#exec-timeout Router(config)#line console 0 Router(config-line)#logging synchronous Modifies console session timeout Redisplays interrupted console input

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-8 Router(config)#interface type number Router(config-if)# type includes serial, ethernet, token ring, fddi, hssi, loopback, dialer, null, async, atm, bri, tunnel, and so on number is used to identify individual interfaces Router(config-if)#exit Quits from current interface configuration mode Router(config)#interface type slot/port Router(config-if)# For modular routers, selects an interface Configuring an Interface

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-9 Enter Global Configuration Mode Router(config-if)#clock rate Router(config-if)# Router(config)#interface serial 0/0 Router(config-if)# Router#configure terminal Router(config)# Router(config-if)#bandwidth 64 Router(config-if)#exit Router(config)#exit Router# Specify Interface Set Clock Rate (on DCE interfaces only) Set Bandwidth (recommended) Configuring a Serial Interface

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-10 Router#configure terminal Router(config)#interface serial 0 Router(config-if)#no shutdown %LINK-3-UPDOWN: Interface Seria0, changed state to up %LINEPROTO-5-UPDOWN: Line Protocol on Interface Serial0, changed state to up Enables an interface that is administratively shut down Router#configure terminal Router(config)#interface serial 0 Router(config-if)#shutdown %LINK-5-CHANGED: Interface Serial0, changed state to administratively down %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down Administratively turns off an interface Disabling or Enabling an Interface

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-11 Unique addressing allows communication between end stations. Path choice is based on destination address. Configuring IP Addresses

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-12 Router show interfaces Command

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-13 Interpreting the Interface Status

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-14 Verifying a Serial Interface Configuration

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-15 Shows the cable type of serial cables Serial Interface show controller Command

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-16 Summary From the privileged EXEC mode, the global configuration mode can be entered, providing access to other configuration modes such as the interface configuration mode or line configuration mode. The CLI will be used to configure the router name, password, and other console commands. The main function of a router is to relay packets from one network device to another. To do this, the characteristics of the interfaces through which the packets are received and sent must be defined. Interface characteristics such as the IP address and bandwidth are configured using the interface configuration mode.

© 2004 Cisco Systems, Inc. All rights reserved. INTRO v2.0—8-17 Summary (Cont.) In a TCP/IP environment, end stations communicate seamlessly with servers or other end stations. This communication occurs because each node using the TCP/IP protocol suite has a unique 32-bit logical IP address. When the router interface configuration has been completed, it can be verified by using show commands.