Re: issue with pptp plugin

[Trey Nolen <support internetpro net>]

On Wed, 2009-06-17 at 08:11 -0500, Trey Nolen wrote:
> 
> On Tue, 2009-06-16 at 15:40 +0200, Axel wrote:
> > Le 15/06/2009 14:15, Trey Nolen a écrit :
> > > Jun 15 07:09:57 stuggots NetworkManager:<info>   Maximum Segment Size
> > > (MSS): 0
> > >    
> > 
> > It could be the problem. It seems that no MTU is defined.
> > Once your VPN connection is established, try to type the command : "sudo 
> > ifconfig ppp0 mtu 1412" in a terminal and try again to create some 
> > traffic, like your remote desktop session.
> > 
> > It may be related to this bug : 
> > http://bugzilla.gnome.org/show_bug.cgi?id=559116 , but from this bug : 
> > "Latest 0.7.1rc1 PPTP plugin uses 1400 as the default MTU." but your 
> > version looks like to be 0.7.1rc4.
> 
> I found that bug, too. You may have missed one of my later emails where
> I state that I have an MTU of 1400 when I am connected.  Below is output
> from ifconfig when I'm connected:
> 
> ppp0      Link encap:Point-to-Point Protocol  
>           inet addr:192.168.4.107  P-t-P:192.168.4.107
> Mask:255.255.255.255
>           UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1400  Metric:1
>           RX packets:11 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:11 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:3 
>           RX bytes:291 (291.0 B)  TX bytes:228 (228.0 B)
> 
> 
> 
> 
> I did try your suggestion of changing the MTU to 1412, but it had no
> effect.  I run Hardy (Ubuntu 8.04) on another of my computers and I have
> noticed that the inet address and the P-t-P address are different when
> I'm connected to a VPN with it. Could that be a source of the issue?
> 


Well, I know there wasn't much interest in this issue, but I finally
resolved it so I figured I'd post the resolution anyway. 

At home, I was able to reproduce the problem with both my desktop and my
laptop (both running Jaunty).   I went to a restaurant that had wifi
with my laptop and noticed that my VPNs would stay connected.  So, I
realized it had to be something on my home network.  Since MTUs had been
mentioned before (regarding the PPP interface), I adjusted those on my
router, and it fixed the problem.  Normally, when I have an MTU issue on
a router connected to the internet, it results in problems with certain
websites and/or slow speed on sites.  I had neither of these issues, but
the VPNs would drop and now do not.  Maybe this will help someone else
with this unusual issue.


Trey Nolen