l2tpd configuration file :
remote access vpn configuration conn L2TP-PSK authby=psk pfs=no rekey=no keyingtries=3 keyexchange=ikev1 forceencaps=yes leftfirewall=yes leftnexthop=%defaultroute type=transport
# ----------------------------------------------------------
# The VPN server.
#
# Allow incoming connections on the external network interface.
# If you want to use a different interface or if there is no
# defaultroute, you can use: left=your.ip.addr.ess
#
left=10.102.222.125
#
leftprotoport=17/1701
# If you insist on supporting non-updated Windows clients,
# you can use: leftprotoport=17/%any
#
# ----------------------------------------------------------
# The remote user(s).
#
# Allow incoming connections only from this IP address.
right=%any
# If you want to allow multiple connections from any IP address,
# you can use: right=%any
#
rightprotoport=17/%any
#
# ----------------------------------------------------------
# Change 'ignore' to 'add' to enable this configuration.
#
rightsubnetwithin=0.0.0.0/0
auto=add
Client was able to connect to server without any preshared key at client side instead it was able to L2TP/Ipsec with Certificate .
how to block connection with L2tp/Ipsec with certificate at server side and allow only L2tp/Ipsec with pre shared key
Strongswan version 5.7 , windows os [client]: 10
