MSVPN Help [Solved]

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

I'm going insane at this point. I haven't been able to get pptpclient to connect to my vpn at work for months. No matter how I switch the options around, the farthest I can get is this:

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

Bump.

Napalm Llama · Guru Joined: 04 Jun 2005 Posts: 533 Location: Cardiff, UK

Could you post the contents of your /etc/ppp/options.pptp file? That should be where most of the configuration is. (I set up PPTP a few months ago, so some of the finer details have escaped my mind)
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jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

Sure.

Napalm Llama · Guru Joined: 04 Jun 2005 Posts: 533 Location: Cardiff, UK

Try adding this to it:

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

No Dice. Sadly the same error:

mrness · Posted: Tue May 22, 2007 5:08 am Post subject:

As the error says, you are not using the right authentication, probably because the authentication info is not found in /etc/ppp/chap-secrets.
Post all the relevant information (entire LCP log, pppd command line, ...) if you want more help.

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

Here is the complete log with command:

mrness · Posted: Wed May 23, 2007 5:27 am Post subject:

Do you have such line in your /etc/ppp/chap-secrets?

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

Indeed I do

domain\\me peer password *

mrness · Posted: Wed May 23, 2007 2:22 pm Post subject:

peer != PPTP

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

That did the trick, I knew it was just something that I was doing wrong. Always is. I'm so happy now. I just need to add my route and I'm ready to rock.

Just a quick clean-up question. According to the wiki, if I did NOT use the mppe kernel patch, which I didn't since I'm on a 2.6 kernel with the support built in, I should NOT be building ppp with the mppe-mppc use flag correct?

mrness · Posted: Wed May 23, 2007 3:32 pm Post subject:

yes, that is correct.

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

Ok, I'm getting there.

VPN now connects successfully and ppp0 is getting an IP from the vpn server. I added my route to the remote network via ppp0, but nothing. I can't ping anything on the remote network.

mrness · Posted: Thu May 24, 2007 4:47 am Post subject:

Some fiirewall (yours or the peer's) is probably to blame.

Napalm Llama · Guru Joined: 04 Jun 2005 Posts: 533 Location: Cardiff, UK

Can you ping the PPP peer itself? (its IP is next to yours in ifconfig ppp0 )

I can ping that, but nothing else - apparently my University's network blocks ICMP traffic.

Also check your routes once everything is up and running - check that the default route is still there, and going through the PPP tunnel, and also check that the route to the VPN server is still through your hardware NIC. pppd plays with the routes, it seems, so I have various scripts that get run at different stages of the login process to revert the damage it causes.
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mrness · Posted: Thu May 24, 2007 11:36 am Post subject:

pppd plays only with a host route to the PPP peer and optionally with default route through ppp interface (controlled by "defaultroute" option).
Other routes you might want should be set through /etc/ppp/{ip-up,ip-down} scripts.

Napalm Llama · Guru Joined: 04 Jun 2005 Posts: 533 Location: Cardiff, UK

But it behaves annoyingly - it won't set a default route if one already exists (ie. it won't replace it). So you need to destroy the default route through your NIC, then if your VPN servers are referred to be domain name rather than IP, as mine are, add a route to your DNS servers, use that to lookup the IPs of the VPN servers, destroy the DNS route (because those servers work funnily unless you talk to them through the tunnel), set routes to the VPN servers, start pppd...

And then do the whole thing in reverse when you stop the tunnel. My point was that routing isn't simple with PPTP.

By the way, jschweg - if you want to borrow my collection of scripts then I'll be more than happy to share

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mrness · Posted: Thu May 24, 2007 11:52 am Post subject:

You can't have 2 default routes with the same metric, but you can have 2 default routes with _different_ metrics.
You should set your primary default route with a metric > 1 (say 5), then pppd will be able to create the default route you want.

Napalm Llama · Guru Joined: 04 Jun 2005 Posts: 533 Location: Cardiff, UK

Now that is worth knowing. I should jump in and help with threads more often - never know what I might learn!

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jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

I only semi-understood what you guys were saying

Below is my routing table AFTER connecting to the VPN and adding the route to the remote internal network:

Napalm Llama · Guru Joined: 04 Jun 2005 Posts: 533 Location: Cardiff, UK

Paste directly from the console into the code tags - don't try and correct fixed-width spacing in the variable-width font of phpBB's reply box

mrness · Posted: Thu May 24, 2007 2:24 pm Post subject:

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

I don't want the internet to go through the VPN, I just need access to the machines on that network. I added the <remotenet> entry myself with this:

route add -net x.x.x.0 netmask 255.255.255.0 dev ppp0

I added that with the intention of telling it to route anything destined for that remote network through ppp0. Am I doing that wrong?

jschweg · Tux's lil' helper Joined: 21 Feb 2004 Posts: 85

Of course the other detail is that even though it connects, it only seems to STAY connected for about a minute, then ppp0 drops. I looked that up on pptpclient's support site and it says that the remote server isn't adhering to some RFC. boo. It could be that the routes are fine, but the link is just spoo.

I never thought that this was going to be a problem considering the vpn router at work has a linux backend and is actually running the same old ppp.