ISDN Dial-On-Demand Sample Configuration
Connecting A Public Network To An ISP Using CHAP Authentication		 Cisco ConfigMaker
Windows 95/NT 4.0 configuration tool

This sample configuration connects a public IP network to an Internet Service Provider (ISP) using PPP and CHAP authentication over an IP unnumbered ISDN connection. It is assumed that the ISP has assigned a registered (public) range of IP addresses for the Local Area Network (LAN) devices that require Internet access. In addition, static routes are used in this example to activate the ISDN line only when needed. This is known as dial-on-demand routing (DDR).

ISP Configuration With PAPGet A Configuration Using PAP Authentication if the ISP uses PAP instead of CHAP
Faxback Doc #0508
PPP TutorialInfo On PPP
Faxback Doc #ppp		 IP Unnumbered TutorialInfo On IP Unnumbered
Faxback Doc #ip_unnum
 

Before You Begin

Detailed IOS Command DescriptionsGet The IOS ISDN Command Glossary.
Faxback Doc #0551
Detailed descriptions of all IOS commands used in ISDN configurations. Also provides links to the IOS Command Reference if more information is required
 IOS Command Line TutorialGet The IOS Command Line Interface Tutorial
Faxback Doc #ios_tutorial
Instructions on configuring an IOS router using the command line interface
Preconfiguration Checklist
ISDN Information
The following info must be gathered from the ISDN service provider
  1. ISDN Switch Type
  2. ISDN SPIDs (where applicable)
    In North America, SPIDs are required for all ISDN switch types except for 5ESS Custom Point-to-point
  3. ISDN Directory Numbers
    The directory number is the local seven digit ISDN phone number (no area codes) of your router
 ISP Information
The following info must be gathered from the ISP
  1. PPP Client Name
    The ISP assigns this name as your login name
  2. PPP Authentication Type
    PAP or CHAP PPP authentication
  3. PPP Password
    The password the ISP will expect you to supply when you login
  4. IP Address Information
    The IP address and subnet mask to be used on the router's local area network (LAN) interface
  5. ISP Phone Number
    ISDN phone number of the ISP

Note: Commands followed by a <*> are on by default and do not have to be configured. The "!" marks that appear in the configuration are automatically entered by the router and function as line separators for easier reading.

Atlanta Router Configuration
In IOS "show running-config" format

version 11.2 <*>
service udp-small-servers <*>
service tcp-small-servers <*>
!
hostname Atlanta
!
enable secret cisco
!
ip subnet-zero
no ip domain-lookup
isdn switch-type basic-ni1
!
interface Ethernet0
 ip address 200.200.200.1 255.255.255.0
!
interface BRI0
 no ip address <*>
 encapsulation ppp
 dialer rotary-group 0
 isdn spid1 014045551111000 5551111
 isdn spid2 014045552222000 5552222
 no fair-queue <*>
 no cdp enable <*>
!
interface Dialer0
 ip unnumbered Ethernet0
 encapsulation ppp
 dialer in-band
 dialer idle-timeout 300
 dialer string 14085553333 class 56K
 dialer hold-queue 10
 dialer load-threshold 200 either
 dialer-group 1
 no fair-queue <*>
 no cdp enable <*>
 ppp authentication chap callin
 ppp chap hostname Atlanta
 ppp chap password gocisco1
 ppp multilink
!
ip classless
ip route 0.0.0.0 0.0.0.0 Dialer0
ip http server
!
map-class dialer 56K
 dialer isdn speed 56
dialer-list 1 protocol ip permit
!
 line con 0
 password console
 login
 line aux 0 <*>
line vty 0 4
 password telnet
 login <*>
!
end <*>

After You've Tried

You've tried the configuration and it doesn't work. Help is available!

IOS Router ISDN Troubleshooting GuideGet IOS Router ISDN Troubleshooting Assistance
Faxback Doc #isdn_ts
 

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