The Care and Feeding of ISDN4BSD
10.1 isdnd.rc Setup	10 Setting up a	10.3 telnet to the

10.2 sppp and isp0 Setup using ispppcontrol and ifconfig

This shell script is used to get the isp0 network interface and its invisible sppp companion configured:

#!/bin/sh

#--------------------------------------

#       ppp example setup

#       last edit-date: [Wed Feb 24 15:53:49 1999]

#--------------------------------------

 

echo "configuring I4BISDN/PPP-interface isp0:"

echo "--------------------"

 

echo ""

echo "removing previous configuration"

ifconfig isp0 delete -link1 down

 

echo ""

echo "setting PPP options"

ispppcontrol isp0 myauthproto=chap

ispppcontrol isp0 myauthname=hmbsd

ispppcontrol isp0 myauthsecret=ganzgeheim

 

echo ""

echo "configuring IP src/dst address, netmask and link flags"

ifconfig isp0 0.0.0.0 192.76.124.10 netmask 0xffffffff link1

 

echo ""

echo "finished"

What does it do ?

In case the isp0 interface was already configured with something, the line

ifconfig isp0 delete -link1 down

puts the isp0 interface into a known state.

ispppcontrol isp0 myauthproto=chap

configures the authorization protocol, our side of the link wants to use CHAP⁶. The other possible protocol to configure here would be PAP⁷.

ispppcontrol isp0 myauthname=hmbsd

sets the system name to hmbsd and

ispppcontrol isp0 myauthsecret=ganzgeheim

sets the password to ganzgeheim to authorize ourselves to the remote PPP stack.

Finally the line

ifconfig isp0 0.0.0.0 192.76.124.10 netmask 0xffffffff link1

configures the isp0 interface:

• [0.0.0.0]setting the own IP address to 0.0.0.0 leaves the local interface IP address open for negotiation. This requires that the remote peer can correctly supply a value for it based on the identity of the caller.
• [192.76.124.10]this is the IP address of the remote system, in this case the Cisco 1003.
• [netmask]this is a point-to-point link and as such the netmask has to be set to 0xffffffff.
• [link1]setting the flag link1 will cause the interface to operate in dial-on-demand mode which means that as soon as an IP packet arrives at the interface isp0, the isdnd will be instructed to dial to the remote side to set up a connection.