ZyXEL Communications P-334W - Manual (Page 230)

Prestige 334W User’s Guide
16-20 VPN Screens
The following table describes the labels in this screen.
Table 16-8 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