[vpn-help] Established VPN tunnel by Ubuntu client only transfers limited userland data

[Gordon]

Hi Matthew,

Thanks for getting back to me on this.

I've looked around for any MTU setting on the Netgear router, and can
only find one reference to this. The router has a default MTU size of
1500 on the WAN interface. 

I was sort of expecting that there might be some MTU setting within the
VPN functionality of the router, but none is apparent.

Anyway,I've tried reducing this WAN MTU downwards, as far as 1300, with
no apparent change in the Linux client behaviour.

Is this enough info to move forward with?

Thanks,
Gordon




On Mon, 2010-11-15 at 22:48 -0600, Matthew Grooms wrote:
> On 11/8/2010 6:31 AM, Gordon wrote:
> > Hi,
> >
> > I have tried both Windows Vista and Ubuntu 10.04 client machines to
> > establish the tunnel to a Netgear router. The Vista client is working
> > fine with the same tunnel configuration.
> >
> > VPN Client Version - 2.1.5, 2.1.7
> > Linux or BSD OS Version - Ubuntu 10.04, 10.10
> > Gateway Make/Model - Netgear FVG318
> > Gateway OS Version - v2.1.2-67N
> >
> > Using the Ubuntu client: a ping to the remote server is successful, a
> > basic text web-page can be retrieved from the server, log in to SQL
> > server is possible, as is showing databases present, and the Netgear
> > router is web manageable through the tunnel.
> >
> > However, it is not possible to transfer images from the web server, and
> > it is not possible to use a database in SQL. Each of these actions
> > completes successfully using the Vista client.
> >
> > I found a previous mailing list report of problems on Linux systems
> > (vpn-help/2008-November/000950.html) which deals with traffic not
> > reaching userland applications. I've followed the suggestions there,
> > setting IP parameters *.rp_filter to 0 on the client. This did not
> > change any of the problem behaviours I'm seeing.
> > The problem occurs every time on the Ubuntu client.
> >
> > Any help getting this working would be appreciated.
> >
> 
> After you initiate the connection, what is the MTU on the TAP device? It 
> could be that large packets are being dropped.
> 
> -Matthew