请参考此配置案例：
ip local pool sales_addresses 209.165.202.129-209.165.202.158
aaa-server sales_server protocol radius
crypto ipsec transform-set sales_l2tp_transform esp-3des esp-sha-hmac
crypto ipsec transform-set sales_l2tp_transform mode transport
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
l2tp tunnel hello 100
group-policy sales_policy internal
group-policy sales_policy attributes
wins-server value 209.165.201.3 209.165.201.4
dns-server value 209.165.201.1 209.165.201.2
vpn-tunnel-protocol l2tp-ipsec
tunnel-group sales_tunnel type remote-access
tunnel-group sales_tunnel general-attributes
address-pool sales_addresses
authentication-server-group none
accounting-server-group sales_server
default-group-policy sales_policy
tunnel-group sales_tunnel ppp-attributes
authentication pap