ZyXEL Communications P-334 - Manual (Page 172)

Prestige 334 User’s Guide
171 Chapter 15 VPN Screens
The following table describes the labels in this screen.
Table 52 VPN IKE: Advanced
LABEL DESCRIPTION
Active Select this check box to activate this VPN policy.
Keep Alive Select this check box to turn on the Keep Alive feature for this SA.
Turn on Keep Alive to have the Prestige 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.
NAT Traversal 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 port 500 to the IPSec router behind the NAT
router.
IPSec Keying Mode The advanced configuration page is only available with the IKE IPSec keying
mode.
Click the Basic button below in order to be able to choose the Manual IPSec
keying mode.
Make sure the remote gateway has the same configuration in this field.
Protocol Number Enter 1 for ICMP, 6 for TCP, 17 for UDP, etc. 0 is the default and signifies any
protocol.
Enable Replay
Detection
As a VPN setup is processing intensive, the system is vulnerable to Denial of
Service (DOS) attacks The IPSec receiver can detect and reject old or
duplicate packets to protect against replay attacks. Enable replay detection by
setting this field to Yes.
Local Address The local IP address must be static and correspond to the remote IPSec
router's configured remote IP addresses.
Two active SAs can have the same 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.
Local Port Start 0 is the default and signifies any port. Type a port number from 0 to 65535.
Some of the most common IP ports are: 21, FTP; 53, DNS; 23, Telnet; 80,
HTTP; 25, SMTP; 110, POP3
Local Port End Enter a port number in this field to define a port range. This port number must
be greater than that specified in the previous field (or equal to it for configuring
an individual port).
Remote Address Start Remote IP addresses must be static and correspond to the remote IPSec
router's configured local IP addresses. The remote address fields do not apply
when the Secure Gateway Address field is configured to 0.0.0.0. In this case
only the remote IPSec router can initiate the VPN.
Two active SAs cannot have the local and remote IP address(es) both the
same. Two active SAs can have the same 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.
Enter a (static) IP address on the network behind the remote IPSec router.