P-334U/P-335U User’s Guide

Table 52 Security > VPN > Rule Setup: IKE (Basic) (continued)

LABEL

DESCRIPTION

 

 

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.

 

Note: The remote IPSec router must also have NAT traversal

 

enabled. See Section 13.1.2.5 on page 143 for more

 

information.

 

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.

 

 

IPSec Keying

Select IKE or Manual from the drop-down list box. IKE provides more protection

Mode

so it is generally recommended. Manual is a useful option for troubleshooting if

 

you have problems using IKE key management.

 

 

DNS Server (for

If there is a private DNS server that services the VPN, type its IP address here.

IPSec VPN)

The ZyXEL Device assigns this additional DNS server to the ZyXEL Device'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 Policy

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.

 

 

Local Address

For a single IP address, enter a (static) IP address on the LAN behind your

 

ZyXEL Device.

 

For a specific range of IP addresses, enter the beginning (static) IP address, in a

 

range of computers on your LAN behind your ZyXEL Device.

 

To specify IP addresses on a network by their subnet mask, enter a (static) IP

 

address on the LAN behind your ZyXEL Device.

 

 

Local Address End

When the local IP address is a single address, type it a second time here.

/Mask

When the local IP address is a range, enter the end (static) IP address, in a range

 

of computers on the LAN behind your ZyXEL Device.

 

When the local IP address is a subnet address, enter a subnet mask on the LAN

 

behind your ZyXEL Device.

 

 

Remote Policy

Remote IP addresses must be static and correspond to the remote IPSec router's

 

configured local IP addresses. The remote fields do not apply when the Secure

 

Gateway IP 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.

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Chapter 13 IPSec VPN