[pptp-server] pptp client

[Michael Barsalou]

I am putting together a section for the HOWTO about using the 
pptp client.  I have a good deal of information, but I am not quite 
sure how much is accurate.  I will tell what I believe and hopefully 
we can straighten out most of my misconceptions.

The pptp command line is:

pptp (IP of destination) (pppd style options)

To make it easier for me I have used the following setup.
My command line looks like this:

pptp (destination-ip) call (destination-name)

The destination-ip is any valid IP address that has some form of 
pptpd running on it.  The destination-name is the name of the file 
that I store in the directory /etc/ppp/peers

This file holds any pppd options you might need for the connection. 
Although there are many options that could be used, here are the 
ones that seem most useful.

noauth
debug
proxyarp
name

To learn more detail about these options look at the man page for 
pppd. (man pppd)

One option I would like to talk about in a little more detail is the 
name option.  This option allows you to specify which name in the 
Chap-secrets file that you want to use when authenticating to the 
remote machine.

In most cases (all?) you have to have identical entries in the chap-
secrets files on both machines.  Since I am using Windows 
networks on either side of the connection my chap-secrets file (on 
both machines) looks something like this:

WindowsDomain\\username	*	password	*

So when using the name option, your options file would look like:

noauth
debug
proxyarp
name WindowsDomain\\username


Here is the part that gets kind of fuzzy for me. Routing.

When you make the connection to the remote machine, your new 
interface will get assigned an IP address from the remote pptpd 
daemon.

If you wanted all you traffic to travel over that link you would just set 
the default route to go to the new link. (Maybe use the defaultroute 
option in your peer file?)

But what if you only want some traffic?  This is where I need help.

Machine A is the gateway for the entire company.
Machine B is the gateway for a remote office.

Each office handles their own traffic, to and from the internet.

All mail traffice needs to go to Machine A.

What do I need to do to make this work?

Thanks for the help.

Mike Barsalou


Michael Barsalou
barjunk at attglobal.net