[Openswan Users] File transfer speed slowing down

[alet at librelogiciel.com]

Hi,

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

Roadwarrior is a physical machine with an Intel(R) Celeron(R) CPU
3.20GHz

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.

Is this behavior to be expected wrt my hardware configuration ?

If not do you have any idea of from where the problem might come ?

Here's my xl2tpd.conf :

[global]
port = 1701
access control = no
rand source = dev

[lac MYVPN]
lns = xx.xx.xx.xx
pppoptfile = /etc/ppp/options.l2tpd.client
challenge = no
refuse chap = yes
require pap = yes
require authentication = no
redial = yes
redial timeout = 15
max redials = 5
hidden bit = yes
length bit = yes
ppp debug = no
tunnel rws = 4
flow bit = yes

And in my pppd options file :

user william
login
ipcp-accept-local
ipcp-accept-remote
require-pap
refuse-chap
refuse-mschap
refuse-mschap-v2
noccp
noauth
noipdefault
crtscts
idle 1800
mtu 1410
mru 1410
defaultroute
lock
proxyarp
connect-delay 5000
usepeerdns


Thanks in advance for any help

Jerome Alet