As part of a broader organisational restructure, data networking research at Swinburne University of Technology has moved from the Centre for Advanced Internet Architecture (CAIA) to the Internet For Things (I4T) Research Lab.

Although CAIA no longer exists, this website reflects CAIA's activities and outputs between March 2002 and February 2017, and is being maintained as a service to the broader data networking research community.

This page is part of the LIFE project.

User Machine Configuration

In our system the user machine PPP's into the NAS and upon authentication and authorisation, can access the ITS through the NAS. Before the PPP connection comes up, the client machine has a private IP address and is allocated a private tun0 IP address. In our system there is only one user so the client does not need to enter their username and password. It is automatically sent to the NAS during the PPP connection initialisation.


As with the NAS we need to add the psuedo-device tun into the FreeBSD kernel for our PPP connection between the user machine and the NAS. This is done by adding the following line to the "/usr/src/sys/i386/conf/GENERIC" file and recompiling the kernel:

psuedo-device tun N # where N is the number of tunnel devices you want to add, this can be left as blank


The following is the configuration added to our "/etc/ppp/ppp.conf" file:

set device
set dial
set timeout 0 # never timeout the connection
set log Phase Chat Connect hdlc LCP IPCP IPV6CP CCP tun
set ifaddr
add default HISADDR
allow users
set authname steve #automatically send this username upon PPP connection initialisation
set authkey testing #automatically send this password upon PPP connection initialisation

The following is the ifconfig of the user machine interface sis0:

sis0:flags=8843 mtu 1500
inet netmask 0xffffff00 broadcast
inet6 fe80::20c:6eff:fed1:58f3%sis0 prefixlen 64 scopeid 0x1
ether 00:0c:6e:d1:58:f3
media: Ethernet autoselect (100baseTX )
status: active


The following is an extract of the "/etc/rc.conf" file for the user machine:

ifconfig_sis0="inet netmask"

Note that there was no default route specified in our configuration. When the user initiates the PPP connection, the ppp.conf file specifies to the user machine the fxp1 interface IP address of the NAS through its sis0 interface.

Starting a PPP Connection

To initialise a PPP connection, the user would need to enter the following lines at the command prompt:

userComp#ppp nas
ppp ON userComp>open

The first command specifies that the "nas:" block be read from the ppp.conf file. The username and password are sent to the NAS on the "open" command. As the connection is established the three P's in the command prompt "ppp ON userComp>" should be converted to capital P's. If this does not occur, there is a problem with the configuration settings, or the physical line is down. The system is now complete and a PPP connection that will allow the user machine to access an outside network will be enabled.

Swinburne Homepage Site Map Search Index

Swinburne Copyright and disclaimer Privacy Feedback

Last Updated: Thursday 19-Feb-2004 12:01:38 AEDT
Maintained by: Ana Pavlicic
Authorised by: Grenville Armitage

IndexSearchSite MapSwinburne Home Page