ZyXEL Communications P-793H v3 User Manual page 135

Table 48 Security > VPN > Setup > Edit
LABEL DESCRIPTION
Secure Gateway Type the WAN IP address or the URL (up to 31 characters) of the IPSec router
Address 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 IPSec Key Mode 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.
Security Protocol
VPN Protocol 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).
Pre-Shared Key Click the button to use a pre-shared key for authentication, and type in your
pre-shared key. A pre-shared key identifies a communicating party during a
phase 1 IKE negotiation. It is called "pre-shared" because you have to share it
with another party before you can communicate with them over a secure
connection.
Type from 8 to 31 case-sensitive ASCII characters or from 16 to 62 hexadecimal
("0-9", "A-F") characters. You must precede a hexadecimal key with a "0x"
(zero x), which is not counted as part of the 16 to 62 character range for the
key. For example, in "0x0123456789ABCDEF", "0x" denotes that the key is
hexadecimal and "0123456789ABCDEF" is the key itself.
Both ends of the VPN tunnel must use the same pre-shared key. You will receive
a "PYLD_MALFORMED" (payload malformed) packet if the same pre-shared key
is not used on both ends.
Encryption Select DES, 3DES, AES or NULL from the drop-down list box.
Algorithm
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.
Note: The DES encryption algorithm is not supported at the time of writing.
Authentication Select SHA1 or MD5 from the drop-down list box. MD5 (Message Digest 5) and
Algorithm 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.
Back Click Back to return to the previous screen.
Apply Click Apply to save your changes back to the P-79X.
Cancel Click Cancel to begin configuring this screen afresh.
Advanced Setup Click Advanced Setup to configure more detailed settings of your IKE key
management.
Chapter 13 VPN
P-79X Series User's Guide
135