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

[Matthew Grooms]

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