Ike Phases; Figure 84 Two Phases To Set Up The Ipsec Sa - ZyXEL Communications Prestige 661H Series User Manual

Table 58 VPN IKE (continued)
LABEL
Authentication
Algorithm
Advanced
Back
Apply
Cancel
Delete

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 84 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.
Chapter 15 VPN Screens
DESCRIPTION
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.
Click Advanced to configure more detailed settings of your IKE key management.
Click Back to return to the previous screen.
Click Apply to save your changes back to the Prestige.
Click Cancel to begin configuring this screen afresh.
Click Delete to delete the current rule.
Prestige 661H/HW Series User's Guide
188