Draytek Vigor3900 Series User Manual page 231

Perfect Forward
Secrecy Status
Dead Peer
Detection Status
DPD Delay
DPD Timeout
5. After filling the required information for Advanced, click the GRE tab to open the
following page.
Available parameters are listed as follows:
Item
Enable GRE
Function
Local GRE IP
Remote GRE IP
Auto Generate
Vigor3900 Series User's Guide
Enables the PFS function. A new Diffie-Hellman Key
Exchange is included every time an encryption and/or
authentication key are computed on PFS.
Enable – Click it to enable DPD. When there is no traffic
through the IPSec tunnel, both server and the client will send
the DPD packet to each other to ensure the IPSec tunnel
connection is active still.
Disable – Click it to disable DPD.
The keep-alive timer. A Hello message will be emitted
periodically when a tunnel is idle. Use the value 0 to disable
this function. The recommended value is 30 seconds if
enabled.
The timeout timer. The peer will be declared dead once no
acknowledge message is received after timeout value. Use
the value 0 to disable this function. The recommended value
is 120 seconds if enabled.
Description
Check the box to enable the function.
The virtual IP address of the router, specified for this tunnel.
The virtual IP address of the remote client, specified for this
tunnel.
Click Enable to generate the GRE key by the system
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