Cisco Router 850 Series Software Configuration Guide

CH A P T E R
 
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Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide
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Basic Router Configuration
This chapter provides procedures for configuring the basic parameters of your Cisco router, including 
global parameter settings, routing protocols, interfaces, and command-line access. It also describes the 
default configuration on startup.
NoteIndividual router models may not support every feature described throughout this guide. Features not 
supported by a...

 
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Chapter 1      Basic Router Configuration
  Viewing the Default Configuration
Viewing the Default Configuration
When you first boot up your Cisco router, some basic configuration has already been performed. All of 
the LAN and WAN interfaces have been created, console and VTY ports are configured, and the inside 
interface for Network Address Translation has been assigned. Use the show
 running-config...

 
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Chapter 1      Basic Router Configuration
  Viewing the Default Configuration
no aaa new-modelip subnet-zero
!
ip cef
ip ips po max-events 100
no ftp-server write-enable!
interface FastEthernet0
 no ip address shutdown
!
interface FastEthernet1 no ip address
 shutdown
!interface FastEthernet2
 no ip address
 shutdown!
interface FastEthernet3
 no ip address shutdown
!
interface FastEthernet4
 no ip address...

 
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Chapter 1      Basic Router Configuration
  Information Needed for Configuration
Information Needed for Configuration
You need to gather some or all of the following information, depending on your planned network 
scenario, prior to configuring your network
 If you are setting up an Internet connection, gather the following information:
 –Point-to-Point Protocol (PPP) client name that is assigned as your...

 
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Chapter 1      Basi c Router Configuration
  Configuring Basic Parameters
Configuring Basic Parameters
To configure the router, perform one or more of these tasks:
 Configure Global Parameters
 Configure Fast Ethernet LAN Interfaces
 Configure WAN Interfaces
 Configuring a Loopback Interface
 Configuring Command-Line Access to the Router
A configuration example is presented with each task to show the...

 
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Chapter 1      Basic Router Configuration
  Configuring  Basic Parameters
Configure Fast Ethernet LAN Interfaces
The Fast Ethernet LAN interfaces on your router are automatically configured as part of the default 
VLAN and as such, they are not configured with individual addresses. Access is afforded through the 
VLAN. You may assign the interfaces to other VLANs  if desired. For more information about...

 
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Chapter 1      Basi c Router Configuration
  Configuring Basic Parameters
Configure the ATM WAN Interface
This procedure applies only to the Cisco 857, Cisco 876, Cisco 877 and Cisco 878 models. 
Perform these steps to configure the ATM interface, beginning in global configuration mode:
CommandPurpose
Step 1For the Cisco 878 model only:
controller dsl 0 
mode atm 
exit
Example:
Router(config)# controller...

 
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Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide
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Chapter 1      Basic Router Configuration
  Configuring  Basic Parameters
Configuring a Loopback Interface
The loopback interface acts as a  placeholder for the static IP address and provides default routing 
information.
For complete information on the loopback commands, see the Cisco IOS Release 12.3 
documentation
 set. 
Perform these steps to conf igure a loopback interface:
CommandPurpose
Step...

 
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Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide
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Chapter 1      Basic Router Configuration
  Configuring Basic Parameters
Verifying Your Configuration
To verify that you have properly configured the loopback interface, enter the show interface loopback 
command. You should see verification output similar to the following example.
Router# show interface loopback 0
Loopback0 is up, line protocol is up 
  Hardware is Loopback  Internet address is...

 
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Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide
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Chapter 1      Basic Router Configuration
  Configuring Basic Parameters
For complete information about the command line commands, see the Cisco IOS Release 12.3 
documentation set. 
Step 3login
Example:
Router(config)# loginRouter(config)# 
Enables password checking at terminal session 
login.
Step 4exec-timeout minutes [seconds]
Example:
Router(config)# exec-timeout 5 30
Router(config)# 
Sets the...