VPN
Gateway to Gateway
90 Cisco Small Business RV320/RV325 Administration Guide
8
•NAT Traversal—Network Address Translation (NAT) enables users with
private LAN addresses to access Internet resources by using a publicly
routable IP address as the source address. However, for inbound traffic, the
NAT gateway has no automatic method of translating the public IP address
to a particular destination on the private LAN. This issue prevents
successful IPsec exchanges. If your VPN router is behind a NAT gateway,
check this box to enable NAT traversal. The same setting must be used on
both ends of the tunnel.
•Dead Peer Detection (DPD)—Sends periodic HELLO/ACK messages to
check the status of the VPN tunnel. This feature must be enabled on both
ends of the VPN tunnel. Specify the interval between HELLO/ACK
messages in the Interval field.
•Extended Authentication—Uses an IPsec host username and password to
authenticate the VPN clients or it uses the user database found in User
Management. Both IPSec host and edge device must enable Extended
Authentication. To use the IPsec Host, click the radio button and enter the
User Name and Password. To use the Edge Device, click the radio button
and select the database from the drop-down menu. To add or edit the
database, click Add/Edit to display the User Management window.
•Tunnel Backup—When DPD determines that the remote peer is unavailable,
this feature enables the router to reestablish the VPN tunnel by using either
an alternative IP address for the remote peer or an alternative local WAN
interface. Check the box to enable this feature and enter the following
settings. This feature is available only if Dead Peer Detection is enabled.
-Remote Backup IP Address—Alternative IP address for the remote
peer, or reenter the WAN IP address that was already set for the remote
gateway.
-Local Interface—WAN interface to use to reestablish the connection.
-VPN Tunnel Backup Idle Time—When the router boots up and the
primary tunnel is not connected within the specified period, the backup
tunnel is used. The default idle time is 30 seconds.