D-Link DIR-853 User Manual page 185

DIR-853 AC1300 MU-MIMO Wi-Fi Gigabit Router
with 3G/LTE Support and USB Port 3.0
User Manual
Parameter
Interface
NAT Traversal
Exchange mode
Enable DPD
DPD delay
The maximum
number of failures
DPD
Select a WAN connection through which the tunnel will pass. When
the Automatic value is selected, the router uses the default WAN
connection.
The NAT Traversal function allows VPN traffic to pass through the
NAT-enabled router.
Select the Disabled value to disable the function.
Select the Enabled value to enable the function if it is supported by a
remote host.
Select the Force value to make the function be always on even if it is
not supported by a remote host.
Select the mode of negotiation from the drop-down list:
Main: The mode provides the most secure communication between
the parties in the course of negotiation of the authentication
procedures.
Base: The draft negotiation mode with preliminary authentication of
a host.
Aggressive: The mode provides faster operation as it skips several
stages of negotiation of the authentication procedures.
Move the switch to the right to enable using DPD protocol for this
tunnel. Such a setting allows to check the status of a remote host: if
encrypted packets exchange between the router and the remote host
breaks down, the router starts sending DPD messages to the remote
host. If the switch is moved to to the left, the DPD delay and The
maximum number of failures DPD fields are not available for
editing.
A time period (in seconds) between attempts to check the status of a
remote host. By default, the value 5 is specified.
A number of DPD messages that were sent to check the status of a
remote host and left unanswered. By default, the value 3 is specified.
If a remote host does not answer the specified number of messages,
the router breaks down the tunnel connection, removes the encryption
keys, and tries to activate the connection.
Page 185 of 228
Configuring via Web-based Interface
Description