Prestige 334 User’s Guide

Table 51 VPN: Rule Setup (Basic)

LABEL

DESCRIPTION

 

 

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-1for maximum security.

Advanced

Click Advanced to configure more detailed settings of your IKE key

 

management.

Apply

Click Apply to save your changes back to the Prestige.

 

 

Reset

Click Reset to begin configuring this screen afresh.

 

 

15.11 IKE Phases

There are two phases to every IKE (Internet Key Exchange) negotiation – phase 1 (Authentication) and phase 2 (Key Exchange). A phase 1 exchange establishes an IKE SA and the second one uses that SA to negotiate SAs for IPSec.

Figure 65 Two Phases to Set Up the IPSec SA

In phase 1 you must:

•Choose a negotiation mode.

•Authenticate the connection by entering a pre-shared key.

•Choose an encryption algorithm.

•Choose an authentication algorithm.

•Choose a Diffie-Hellman public-key cryptography key group (DH1 or DH2).

Set the IKE SA lifetime. This field allows you to determine how long an IKE SA should stay up before it times out. An IKE SA times out when the IKE SA lifetime period expires. If an IKE SA times out when an IPSec SA is already established, the IPSec SA stays connected.

In phase 2 you must:

• Choose which protocol to use (ESP or AH) for the IKE key exchange.

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Chapter 15 VPN Screens