L2TP/IPSEC on Cisco ASA

This is the configuration for L2TP/IPSEC on Cisco ASA.
This assumes that there is an aaa-server configured named ad_vpn for vpn users.
When using aaa-server protocol ldap then only pap is valid authentication type.
If you use radius authentication instead of ldap then ms-chap-v2 authentication can be enabled.

ip local pool vpnclient 172.16.20.100-172.16.20.120 mask 255.255.255.0

access-list vpnclient_splitTunnelAcl remark Internal
access-list vpnclient_splitTunnelAcl standard permit 192.168.45.0 255.255.255.0

group-policy vpnclient internal
group-policy vpnclient attributes
vpn-tunnel-protocol IPSec l2tp-ipsec
split-tunnel-policy tunnelspecified
split-tunnel-network-list value vpnclient_splitTunnelAcl
intercept-dhcp enable

tunnel-group DefaultRAGroup general-attributes
address-pool vpnclient
authentication-server-group ad_vpn
default-group-policy vpnclient
strip-realm
strip-group
tunnel-group DefaultRAGroup ipsec-attributes
pre-shared-key *****
tunnel-group DefaultRAGroup ppp-attributes
authentication pap
no authentication chap
no authentication ms-chap-v1

crypto ipsec ikev1 transform-set l2tp1 esp-aes esp-sha-hmac
crypto ipsec ikev1 transform-set l2tp1 mode transport
crypto ipsec ikev1 transform-set l2tp2 esp-aes esp-md5-hmac
crypto ipsec ikev1 transform-set l2tp2 mode transport
crypto ipsec ikev1 transform-set aes-256-l2tp esp-aes-256 esp-sha-hmac
crypto ipsec ikev1 transform-set aes-256-l2tp mode transport

crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set transform-set l2tp1 l2tp2 aes-256-l2tp
no crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set pfs

crypto isakmp nat-traversal 20

crypto ikev1 policy 5
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 86400
crypto ikev1 policy 10
authentication pre-share
encryption aes
hash sha
group 2
lifetime 86400

crypto ikev1 enable outside