Debian – L2TP over IPSEC strongswan/xl2tpd slow connection debian 9 and 10

debianipsecl2tpstrongswan

I have tried almost anything – my internet connection 500 Mbit/s
I connect from the same external IP subnet so my speed to the server is also 500 Mbit/s.

When i use wget from my l2tp server i have 450 Mbit/s download.
When i connect to this server from windows host via l2tp/ipsec and do speed test of the internet connection i get around 1.5 Mbit/s

my Strongswan ipsec.conf:

config setup

conn %defult
    ikelifetime=28800s
    lifetime=3600s
    keyingtries=1
    keyexchange=ikev1

conn L2TP
    ike=aes256-sha256-modp1024
    esp=aes256-sha256
    authby=secret
    left=212.14.7.22
    leftid=212.14.7.22
    leftprotoport=17/%any
    rightprotoport=17/%any
    right=%any
    rightsubnet=0.0.0.0/0
    ikelifetime=8h
    keylife=1h
    rekey=no
    auto=add
    type=transport
    fragmentation=yes
    dpddelay=30
    dpdtimeout=120
    dpdaction=clear

conn clear
    auto=ignore

My xl2tpd.conf:

[global]
  port = 1701

[lns default]
  ip range = 10.111.111.2-10.111.111.102
  local ip = 10.111.111.1
  require chap = yes
  refuse pap = yes
  require authentication = yes
  name = hub-d10-l2tpd
  ppp debug = yes
  pppoptfile = /etc/ppp/options.xl2tpd
  length bit = yes

my options.xl2tpd:

ipcp-accept-local
ipcp-accept-remote
require-mschap-v2
ms-dns 8.8.8.8
proxyarp
noccp
auth
debug
defaultroute
idle 1800
mtu 1280
mru 1280
connect-delay 5000

Iptables as easy as it can be:

# Generated by xtables-save v1.8.2 on Thu Jul 11 09:00:00 2019
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A POSTROUTING -s 10.111.111.0/24 -o ens192 -j MASQUERADE
COMMIT
# Completed on Thu Jul 11 09:00:00 2019

I have tried to change mtu/mru from 1200 to 1420 – didn't helped.
This is fresh Debian 10 install but i have also tried on Deb 9.
Any ideas ?

Best Answer

OK, finally have found a problem. It was my laptop poor performance. I have tested it now on intel core i7 client and achieved 285Mbit/s. It coud be more but i7 still is bottleneck:

speed: 285Mbit/s
client side cpu usage 95%  
server side cpu usage 14%

Greetrings. Kris