[OpenVPN home] [Date Prev] [Date Index] [Date Next]
[OpenVPN mailing lists] [Thread Prev] [Thread Index] [Thread Next]
Google
 
Web openvpn.net

Re: [Openvpn-users] Re: Odd Tunnel Problems


  • Subject: Re: [Openvpn-users] Re: Odd Tunnel Problems
  • From: "James Yonan" <jim@xxxxxxxxx>
  • Date: Fri, 10 Oct 2003 22:59:59 -0000

AthlonRob <AthlonRob@xxxxxxxx> said:

> On Tue, 2003-10-07 at 00:29, Luc Van der Veken wrote:
> > On Mon, 06 Oct 2003 19:33:05 -0700, AthlonRob <AthlonRob@xxxxxxxx>
> > wrote:
> > 
> > > Any idea what might be up with this?  MTU problem, maybe?  I don't know
> > > what the symptoms of that would be... or how it might relate to the tap0
> > > interface being bridged....
> <snip>
> > That sounds a bit similar to your symptoms, so I'd try with a lower
> > MTU.
> 
> Indeed, it was.
> 
> I manually dropped the MTU down to 1400 yesterday and tried connecting
> again.  Same symptoms.
> 
> So I tried the fixmss option - that did the trick!  I saw it mention an
> MTU level down around 1330 or so.  I don't know if that's what it set it
> to or what.

With the latest beta, you can start up the connection with --mtu-test on one
side and it will actually measure the MTU going in both directions.

You can then set your --mssfix parameter to the result given by --mtu-test.  

The advantage of using this approach is in performance, because you will be
using close to the largest packet size the UDP connection can support without
hitting the drop zone.

James


____________________________________________
Openvpn-users mailing list
Openvpn-users@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/openvpn-users