[root@td-gw0 strongswan]# cat /etc/strongswan/ipsec.conf | egrep '^$|^#' -v
config setup
        # strictcrlpolicy=yes
        # uniqueids = no
conn vpnclient
        keyexchange=ikev1
        auto=start
        authby=secret
        type=transport
        left=xxx.xxx.xxx.xxx
        leftprotoport=udp/1701
        rightprotoport=udp/1701
        right=yyy.yyy.yyy.yyy
        pfs=no
        keyingtries=1
        ike=aes128-sha1-modp1024
        esp=aes256-sha1-modp1024

# PSK in file ipsec.secret
#format
 : PSK blablablabla

[root@td-gw0 strongswan]# cat /etc/xl2tpd/xl2tpd.conf | egrep '^$|^#' -v
[global]
access control = yes
[lac itl]
lns = server.name.org
ppp debug = yes
pppoptfile = /etc/ppp/options.l2tpd.client
autodial = yes
name = username
length bit = yes

[root@td-gw0 strongswan]# cat /etc/ppp/options.l2tpd.client | egrep '^$|^#' -v
ipcp-accept-local
ipcp-accept-remote
refuse-eap
require-mschap-v2
noauth
idle 1800
mtu 1450
mru 1450
logfile /var/log/xl2tpd.log
connect-delay 5000
name username
password password123