ZyXEL Communications Prestige 652, User Manual, Page: 196 / 521

Prestige 652 Series User’s Guide
17-12 VPN Screens
Table 17-7 VPN IKE
LABEL DESCRIPTION
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 VPN Setup and
Authentication Algorithm fields (described next).
Pre-Shared Key
Type your pre-shared key in this field. 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. Multiple SAs connecting through a secure
gateway must have the same pre-shared key.
VPN - Setup
Select DES , 3DES or NULL from the drop-down list box.
When DES is used for data communications, both sender and receiver must know
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.
Select
NULL to set up a tunnel without encryption. When you select NULL , you do
not enter an encryption key.
Authentication
Algorithm
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.
Advanced Click Advanced to configure more detailed settings of your IKE key management.
Back Click Back to return to the previous screen.
Apply Click Apply to save your changes back to the Prestige.
Cancel Click Cancel to begin configuring this screen afresh.
Delete Click Delete to delete the current rule.