Cisco Router 826 Routers Software Configuration Guide

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
Backup Interfaces
When the device receives an indication that the primary line is down, the backup interface is brought up. 
You can configure the backup interface to go down (after a specified time) when the primary connection 
is restored. 
The dial-on-demand routing (DDR) backup call is triggered by traffic of...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
Cisco 831 and Cisco SOHO 91 Routers
Support for the dial backup feature on the Cisco 831 router is limited because the Ethernet WAN 
interface is always up, even when ISP connectivity is down across the modem connected to the Cisco 831 
router. Support for dial backup is possible only for the PPPoE environment....

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
Configuring Dial Backup and Remote Management for the Cisco 837 and 
Cisco SOHO 97 Routers
Figure 2-8 shows how dial backup and remote management work in a network system when the primary 
line goes down. 
Figure 2-8 Cisco 837 Router Dial Backup and Remote Management Table 2-2 Encapsulation Types Supported by...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
Configuring Dial Backup and Remote Management for the Cisco 836 and 
Cisco SOHO 96 Routers
Figure 2-9 and Figure 2-10 show how dial backup and remote management work in a network system 
when the primary line goes down. Two scenarios are typical applications of the Cisco 836 and the 
Cisco SOHO 96 routers. In...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
Figure 2-10 Cisco 836 Router Dial Backup and Remote Management—Dial Backup Directly from 
Router to ISDN Switch
PPP over ATM with Centrally Managed Addressing and with Dial Backup
When customer premises equipment such as a Cisco 837 router is connected to an ISP, an IP address is 
dynamically assigned to the...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
Configuration Example
The following configuration example for a Cisco 837 router specifies an IP address for the ATM 
interface via PPP/IPCP address negotiation and dial backup over the console port.
!
version 12.2
no service pad
service timestamps debug uptime
service timestamps log uptime
no service...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
modemcap entry MY-USER_MODEM:MSC=&F1S0=1
chat-script Dialout ABORT ERROR ABORT BUSY ““ “AT” OK “ATDT 5555102\T”
TIMEOUT 45 CONNECT \c
!
!
!
!
interface Ethernet0
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip tcp adjust-mss 1452
hold-queue 100 out
!
interface ATM0
mtu 1492
no ip address
no atm...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
ppp ipcp wins request
ppp ipcp mask request
!
! IP NAT over Dialer interface using route-map
ip nat inside source route-map main interface Dialer1 overload
ip nat inside source route-map secondary interface Dialer3 overload
ip classless
!
! When primary link is up again, distance 50 will override 80 if dial...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
speed 115200
flowcontrol hardware
line vty 0 4
exec-timeout 0 0
password cisco
login
!
scheduler max-task-time 5000
end
Configuring Dial Backup and Remote Management for the Cisco 836 Router
Follow the steps given in the “Configuring the Cisco 836 Router’s ISDN Settings” section on page 2-25 
to configure dial...

  
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Chapter 2      Network Scenarios
Configuring Dial Backup
Configuring Dial Backup and Remote Management Settings
As described in the “Dial Backup Feature Limitations and Configuration” section on page 2-16, backup 
interface, static routes, and dialer watch are the three methods used for implementing dial backup and 
remote management. This section provides detailed...