I've been running Slackware for many years now but I've never had to deal with routing before. Unfortunately the university that I am attending has decided that in order to use their wireless net everyone must access it through a vpn. And of course they use pptp. While I have been using their vpn to login and use the school's engineering servers for months I am just now trying to use the on campus wireless with a new laptop.

I installed the slackbuilds.org pptp package. Setup the pppd and pptp configurations and everything seems to connect but nothing goes through. On my desktop at home all I needed was to put the following into ip-up in order to get rdesktop to connect to the school servers. I can't connect to anything else while pptp is running but it works for what I need it to do. On the laptop I can use rdesktop but I need to have all net traffic go through the vpn connection while I am on campus and I can't figure it out.

I did try the generic suggestions on pptpclient.sourceforge.net/ for routing but they don't work ether.

What my end goal is this: to get on campus, connect to one of their access points with wpa_gui, start up pptp to use their net without having a messed up routing table so I can leave and connect at a local coffee shop without hassle. Can anyone help me with this?

Thanks a lot in advance.

Since you didnt post the routing table once you are connected to vpn ill assume that vpn interface is tun0.

ill assume that ppp0 is interface that have direct access to the internet.

so theres a few way you can do it:

1. you should know the public IP (internet ip) of the vpn that you are connecting to.
ill assume that your default route is right now :

then you do

then by executing you can see that the net traffic will go now through vpn. it will show gateway ip of vpn.

now lets say that gateway of vpn is 10.10.0.1
2. slightly better way would be to define routing like this:

Now first way is good if you really want to test how good is connection between you and vpn ex how long will vpn connection lasts. and when connection drops you will not have access to the internet unless you remove newly created route for vpn and make default route to be ppp0 if ppp0 is of course your default interface that have access to the internet.

and Second way is better because you dont have to remove the old route which is now ppp0 but because its greatly defined it takes precedence over current default route and if vpn connection drops, or you disconnect from the vpn you will still have access to the internet, because your old route which is ppp0 will remain intact.

Thank you for the suggestions, Matters.

I will have to modify your suggestions slightly though as the vpn is not going through tun0 but ppp0 and the laptop is connecting to the general network though wlan0. When I am back on campus tomorrow I will try them. I will also copy the routing table that is originally produced and what is made through your suggestions and post them.

So here are the routing tables from on campus.

Initial connection to an access point:
After starting pptp with pppd and not using a ip-up script:
134.88.252.20 is the address that is used to log into the vpn. The local address given by the vpn is 134.88.249.* and 134.88.248.1 is the remote address. Removing the wlan0 default and setting up a default with 134.88.252.20 or 134.88.248.1 as the gateway or no gateway does not work.

The second suggestion does not work as route keeps saying that the netmask does not make sense.