4. (Optional)I f you usec lientcerti ficates for userauthenticatio n,select the Check certificate commonname
against AAA server checkbox to verify that the certificate's common name exists in the server. This parameteri s
enabledby default in the default-cap and default-rapVPN profiles, and disabled by default on all other VPN
profiles.
5. (Optional)Set Max Authenticati on failuresto an integer value (the default valueis 0,which disables this
feature).
6. Click Apply.
7. In the Default profile menui n the left window pane, select Server Group.
8. From the Server Group drop-down list, select the server group to be used for VPN authenticati on.
9. Click Apply.
To configureV PN authentication via the command-line interface,access t heCLI inconfig mode and issue the
followingco mmands:
(host)(config) #aaa authentication vpn default
cert-cn-lookup
clone
default-role <role>
max-authentication-failure <number>
server-group <name>
Configuring a Ba sic VPN for L2TP/IPsec in the WebUI
The combination of Layer-2 Tunneling Protocol and Internet Protocol Security (L2TP/IP sec) is a highly-secure
technology that enablesV PN connections across public networks such as the Internet. L2TP/IPsec provides bo th a
logical transportmechanism on which to transmit PPP frames as well as tunnelingo rencapsulation so that the PPP
framescan be sent acrossan IP network. L2TP/IPsec relies on the PPP connection process to perform user
authentication and protocol configuration. With L2TP/IPsec, the user authentication process is encrypted using the
Data Encryption Standard (DES) or Triple DES (3 DES) algorithm.
L2TP/IPsec using IKEv1 requires two levels of authentication:
lComputer-levelauthentication with a preshared key to createt heIP sec securityas sociations (SAs) to protect the
L2TP-encapsulateddata.
lUser-levelauthentication through a PPP -basedauthenticati on protocol using passwords, SecureID, digital
certificates, or smart cards after successful creation of the SAs.
NOTE:Note that only Wi ndows 7 clients, StrongSwan 4.3 cli entsand VIAclients support IKEv2. For additional information on the
authenticationtypes supported by thesecl ients, see"Work ing withIKEv2 Clients " on page 273.
Use the following proceduresto configure a remote access VPN for L2TP IPsec for clients using pre-shared keys,
certificates or EAP for authenticati on using the WebUI.
l"Defining Authentication Method and Server Addresses"o n page2 79
l"Defining Address Pools" on page 280
l"EnablingSource NAT" on page 28 0
l"SelectingCertificates" o n page 280
l"Defining IKEv1 Shared Keys" on page 277
l"ConfiguringIKE Policies" on page 281
l"Setting the IPsec Dynamic Map" on page 282
l"FinalizingWebUI changes"o n page 282
DellPowerConnect W- Series ArubaOS 6.2 | UserGuide VirtualPrivate Networks | 275