Title: DECbrouter90, Configuring PPP over a Dial-on-Demand circuit

Product: DECbrouter V9.14/V10.0.

Question:

I'm trying to configure a Dial-on-demand link between the DECbrouter90 and
another 3rd party router. Can someone point me to an example of setting up 
DDR over PPP? Does the interface need to have an IP address? Do i need to 
create an Ip route?

Solution:
    
       If the remote router is initiating the connection, then the
    DECbrouter needs no special setup for DDR. The incoming call from the
    remote site should raise DSR from the modem to the DECbrouter, and the
    DECbrouter will attempt to start a PPP LCP connection. R, assuming that you 
    have applied the "encapsulation PPP" command to the interface. Remember 
    that the serial interface of the DECbrouter is *synchronous*, so 
    synchronous dialup modems must be used, not asynchronous.
    
:Does the interface need to have an IP address? Do i need to create an Ip route?
    
    The serial interface will need to have an address in the same IP subnet
    as the 3rd party router's serial interface, since the DECbrouter's
    implementation of "unnumbered" is cisco-proprietary.

    Re: an IP route, the DECbrouter needs to know about the IP networks
    reachable through the other router, one way or another. You can create
    static routes, or the routers may run a common routing protocol, such
    as RIP or OSPF.
    
:Can someone point me to an example of setting up DDR over PPP? 
    
        If you want the DECbrouter to initiate the connection, here's an
    example of DDR setup from the DECbrouter CDROM. If you wish to use PPP
    encapsulation, just add the command "encapsulation PPP" under
    "Interface s 0" (or "s 1". You should probably also enable PPP
    authentication, such as CHAP, to provide a measure of security for the
    dial-up access. 


    Configuring DDR in an IP Environment Example
    
    The following example illustrates how to use DDR on a synchronous
    interface in an IP environment. 
    
    
    interface serial 1

    ip address 131.108.126.1 255.255.255.0

    dialer in-band

    ! The next command sets the dialer idle time-out to 10 minutes
    
    dialer idle-timeout 600

    ! The next command inserts the phone number

    dialer string 5551234

    ! The next command gives the modem enough time to recognize that
    ! DTR has dropped so the modem disconnects the call

    pulse-time 1

    ! The next command adds this interface to the dialer access group
    ! defined with the dialer-list command

    dialer-group 1
    
    ! The first access list statement, below, specifies that IGRP updates
    ! are not interesting packets. The second access-list statement specifies 
    ! that all other IP traffic such as Ping, Telnet, or any other IP packet 
    ! are interesting packets. The dialer-list command then creates dialer 
    ! access group 1 and states that access list 101 is to be used to classify 
    ! packets as interesting or uninteresting. The ip route commands specify 
    ! that there is a route to network 131.108.29.0 and to network 131.108.1.0 
    ! via 131.108.126.2. This means that several destination networks
    ! are available through a router that is dialed from interface serial 1.
    
    access-list 101 deny igrp 0.0.0.0 255.255.255.255 255.255.255.255
    0.0.0.0

    access-list 101 permit ip 0.0.0.0 255.255.255.255 0.0.0.0
    255.255.255.255
    
    dialer-list 1 list 101

    ip route 131.108.29.0 131.108.126.2

    ip route 131.108.1.0 131.108.126.2