ZyXEL Communications ZyWall 35 User Manual page 255

Table 77 Edit VPN Rule (continued)
LABEL
My Address
Secure Gateway
Address
IPSec Algorithm
ESP
Encryption
Algorithm
Authentication
Algorithm
Chapter 14 VPN Screens
DESCRIPTION
IP Address identifies the WAN IP address of the ZyWALL. You can select IP
Address and enter the ZyWALL's static WAN IP address (if it has one) or leave
the field set to 0.0.0.0. The VPN tunnel has to be rebuilt if the My Address
changes after setup.
The following applies if the My Address field is configured as 0.0.0.0:
• When the WAN port operation mode is set to Active/Passive, the ZyWALL
uses the IP address (static or dynamic) of the WAN port that is in use.
• When the WAN port operation mode is set to Active/Active, the ZyWALL uses
the IP address (static or dynamic) of the primary (highest priority) WAN port to
set up the VPN tunnel as long as the corresponding WAN1 or WAN2
connection is up. If the corresponding WAN1 or WAN2 connection goes down,
the ZyWALL uses the IP address of the other WAN port.
• If both WAN connections go down, the ZyWALL uses the dial backup IP
address for the VPN tunnel when using dial backup or the LAN IP address
when using traffic redirect. See the chapter on WAN for details on dial backup
and traffic redirect.
Select My Domain Name and choose one of the dynamic domain names that you
have configured (in the DDNS screen) to have the ZyWALL use that dynamic
domain name's IP address.
Type the WAN IP address or the URL (up to 31 characters) of the IPSec router
with which you're making the VPN connection. Set this field to 0.0.0.0 if the
remote IPSec router has a dynamic WAN IP address (the Key Management field
must be set to IKE).
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.
Select ESP if you want to use ESP (Encapsulation Security Payload). The ESP
protocol (RFC 2406) provides encryption as well as some of the services offered
by AH. If you select ESP here, you must select options from the Encryption
Algorithm and Authentication Algorithm fields (described below).
Select DES, 3DES, AES or NULL from the drop-down list box.
When you use one of these encryption algorithms for data communications, both
the sending device and the receiving device must use the same secret key, which
can be used to encrypt and decrypt the message or to generate and verify a
message authentication code. The DES encryption algorithm uses a 56-bit key.
Triple DES (3DES) is a variation on DES that uses a 168-bit key. As a result,
3DES is more secure than DES. It also requires more processing power, resulting
in increased latency and decreased throughput. This implementation of AES uses
a 128-bit key. AES is faster than 3DES.
Select NULL to set up a tunnel without encryption. When you select NULL, you
do not enter an encryption key.
Select SHA1 or MD5 from the drop-down list box. MD5 (Message Digest 5) and
SHA1 (Secure Hash Algorithm) are hash algorithms used to authenticate packet
data. The SHA1 algorithm is generally considered stronger than MD5, but is
slower. Select MD5 for minimal security and SHA-1 for maximum security.
ZyWALL 35 User's Guide
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