ZyXEL Communications NBG-4600N User Manual page 201

Table 68 Security > VPN > General > Rule Setup: IKE (Basic) (continued)
LABEL
NAT Traversal
IPSec Keying
Mode
DNS Server (for
IPSec VPN)
Local Policy
Local Address
Local Address
End /Mask
NBG-460N User's Guide
DESCRIPTION
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.
Note: 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 or Manual from the drop-down list box. IKE provides more
protection so it is generally recommended. Manual is a useful option
for troubleshooting if you have problems using IKE key management.
If there is a private DNS server that services the VPN, type its IP
address here. The NBG-460N assigns this additional DNS server to the
NBG-460N'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 NBG-460N.
For a specific range of IP addresses, enter the beginning (static) IP
address, in a range of computers on your LAN behind your NBG-460N.
To specify IP addresses on a network by their subnet mask, enter a
(static) IP address on the LAN behind your NBG-460N.
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 NBG-460N.
When the local IP address is a subnet address, enter a subnet mask on
the LAN behind your NBG-460N.
Chapter 15 IPSec VPN
201