[Openswan Users] File transfer speed slowing down

[Paul Wouters]

On Wed, 5 Jan 2011, alet at librelogiciel.com wrote:

> I've got a problem on a roadwarrior machine when doing file transfers,
> not sure where the problem could come from, and not sure if the problem
> happens elsewhere (not tried yet)

> Both the roadwarrior and VPN gateway use openswan 2.6.28+dfsg-5 and
> xl2tpd 1.2.7+dfsg-1 from Debian.
>
> VPN gateway is a vmware virtual Debian machine running kernel
> 2.6.26-2-686

> When connected (ipsec+l2tp) I transfer a big file either from or to the
> roadwarrior from another machine, not connected to the VPN but which
> uses the VPN gateway precisely as the gateway to connect to the
> roadwarriors, and now the problem begins : the file transfer works but
> is slower and slower and slower. On the roadwarrior side, xl2tpd eats
> all CPU. On the VPN gateway side, xl2tpd eats almost no CPU.

Odd. Can you see if the xl2tpd process is getting bigger? Are you getting
retransmitted packets? This should not happen.

Is this using netkey or klips?

You might need to recompile xl2tpd with more debugging, and log to tmpfs
to get more information on this issue for us.

Paul