ZyXEL Communications NBG5715 User Manual page 126

Chapter 18 IPSec VPN
The following table describes the labels in this screen.
Table 55 Security > IPSec VPN > General > Edit: IKE
LABEL
Property
Propert
Keep Alive
NAT Traversal
IPSec Keying
Mode
DNS Server (for
IPSec VPN)
Local Policy
Local Address
Local Address End
/Mask
126
DESCRIPTION
Select Enable to activate this VPN policy.
Select this check box to have the NBG5715 automatically reinitiate the SA after
the SA lifetime times out, even if there is no traffic. The remote IPSec router
must also have keep alive enabled in order for this feature to work.
Select this check box to enable NAT traversal. NAT traversal allows you to set up
a VPN connection when there are NAT routers between the two IPSec routers.
The remote IPSec router must also have NAT traversal enabled.
You can use NAT traversal with ESP protocol using Transport or Tunnel mode,
but not with AH protocol nor with manual key management. In order for an
IPSec router behind a NAT router to receive an initiating IPSec packet, set the
NAT router to forward UDP ports 500 and 4500 to the IPSec router behind the
NAT router.
Select IKE from the drop-down list box. IKE provides more protection so it is
generally recommended.
If there is a private DNS server that services the VPN, type its IP address here.
The NBG5715 assigns this additional DNS server to the NBG5715's DHCP clients
that have IP addresses in this IPSec rule's range of local addresses.
A DNS server allows clients on the VPN to find other computers and servers on
the VPN by their (private) domain names.
Local IP addresses must be static and correspond to the remote IPSec router's
configured remote IP addresses.
Two active SAs can have the same configured local or remote IP address, but
not both. You can configure multiple SAs between the same local and remote IP
addresses, as long as only one is active at any time.
In order to have more than one active rule with the Secure Gateway Address
field set to 0.0.0.0, the ranges of the local IP addresses cannot overlap
between rules.
If you configure an active rule with 0.0.0.0 in the Secure Gateway Address
field and the LAN's full IP address range as the local IP address, then you cannot
configure any other active rules with the Secure Gateway Address field set to
0.0.0.0.
For a single IP address, enter a (static) IP address on the LAN behind your
NBG5715.
For a specific range of IP addresses, enter the beginning (static) IP address, in a
range of computers on your LAN behind your NBG5715.
To specify IP addresses on a network by their subnet mask, enter a (static) IP
address on the LAN behind your NBG5715.
When the local IP address is a single address, type it a second time here.
When the local IP address is a range, enter the end (static) IP address, in a
range of computers on the LAN behind your NBG5715.
When the local IP address is a subnet address, enter a subnet mask on the LAN
behind your NBG5715.
NBG5715 User's Guide