User's Manual

Virtual Private Networking
115
N600 Wireless Dual Band Gigabit ADSL2+ Modem Router DGND3700
Parameters
(Continued)
SA Life Time The time interval before the SA (security association) expires. (It is
automatically reestablished as required.) While using a short time
period (or data amount) increases security, it also degrades
performance. It is common to use periods over an hour (3600 seconds)
for the SA life-time. This setting applies to both IKE and IPSec SAs.
Enable IPSec PFS
(Pe
r
fect Forward
Secrecy)
• If this check box is selected, security is enhanced by ensuring that
the key is changed at regular intervals. Also, even if one key is
broken, subsequent keys are no easier to break. (Each key has no
relationship to the previous key.)
• This setting applies to both IKE and IPSec SAs. When configuring
the re
mote endpoint to match this setting, you might have to specify
the key group used. For this device, the key group is the same as the
DH Group setting in the IKE section.
General Policy Name Enter a unique name to identify this policy
.
This name is not supplied to
the remote VPN endpoint. It is used only to help you manage the
policies.
Remote VPN
Endp
oint
• The remote VPN endpoint has to have this VPN gateway’s address
entered as its remote VPN endpoint.
• If the remote endpoint has a dynamic IP address, select Dyn
amic IP
address. No address data input is required. You can set up multiple
remote dynamic IP policies, but only one such policy can be enabled
at a time. Otherwise, select an option (IP address or domain name)
and enter the address of the remote VPN endpoint to which you want
to connect.
IKE Keep Alive • If you want to ensure that a connection
is kept open, or, if that is not
possible, that it is quickly reestablished when disconnected, select
this check box.
• The ping IP address has to be associated with the remote endpoint.
The
remote LAN address has to be used. This IP address will be
pinged periodically to generate traffic for the VPN tunnel. The remote
keep-alive IP address has to be covered by the remote LAN IP range
and has to correspond to a device that can respond to ping. The
range should be made as narrow as possible to meet this objective.
Local LAN
The remote VPN
end
p
oint has to
have these IP
addresses entered
as its remote
addresses.
Subnet Mask Enter the network mask.
Single/Start IP
Address
• Enter the IP address for a single address, or the starting address for
an
address range. A single address setting is used when you want to
make a single server on your LAN available to remote users. A range
has to be an address range used on your LAN.
• Any. The remote VPN endpoint might be at any IP address.
Table 19. VPN - Auto Policy screen settings (continued)
Fields and Settings Description