Adding a gateway for ppp?

[mdevin@ozemail.com.au]

I am trying to set up a new ppp connection with pppconfig.  I know the
basics of this and have set up ones through bigpond and ozemail and can
connect to each with pon bigpond / pon ozemail.

Now this time I am trying to connect through my local university (QUT).
I went through the same process in pppconfig and set it up.  It connects
OK and I can see all the local uni web pages etc.  But cannot connect to
any address outside the qut network.

Here is part of /var/log/syslog showing it has connected:
Oct 17 10:53:07 beast pppd[8979]: local  IP address 131.181.144.113
Oct 17 10:53:07 beast pppd[8979]: remote IP address 131.181.144.3
Oct 17 10:53:07 beast pppd[8979]: primary   DNS address 131.181.127.32
Oct 17 10:53:07 beast pppd[8979]: secondary DNS address 131.181.59.48
Oct 17 10:53:07 beast pppd[8979]: Script /etc/ppp/ip-up started (pid 8992)

There are some instructions for Redhat users using Kppp which I don't
want to use if possible.  The instructions talk about setting up a
default gateway which is different to the local and remote IP addresses
I was assigned above.

Here is the relevant part of the instructions for Kppp users:
STEP 7
 In the New Account dialogue window.
 Select the Gateway Tab.
 Check the Static Gateway check box.
 In the Gateway IP Address: box, enter
 131.181.142.1
 Check the Assign the Default Route to this Gateway
 check box.
 Select the OK button.

In step one they also talk about creating a /etc/ppp/ip-up.local file:
STEP 1
 Open a Console
 Create/Edit the file /etc/ppp/ip-up.local;
 Eg. pico /etc/ppp/ip-up.local
 #!/bin/bash
 route add default gw $4
 route del $5 exit 0

All the rest of the instruction seem to be just generic stuff which I
have done with pppconfig - setting the name of the connection, dynamic
ip address assignment, assigning dns servers etc.

So it seems that I need to change the default gateway (I think?)  I
checked the routing table:
# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
dialin13.net.qu *               255.255.255.255 UH    0      0        0 ppp0
default         dialin13.net.qu 0.0.0.0         UG    0      0        0 ppp0

I tried deleting these two routes and then adding a default route to
131.181.142.1 but I am not really sure how to do this.

Can anyone help me here?

Thanks.
Mark.