ZyXEL Communications P-2602H - Manual (Page 250)

Chapter 18 VPN Screens
P-2602H(W)(L)-DxA User’s Guide
250
18.12 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 144 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.
• Choose an encryption algorithm.
• Choose an authentication algorithm
• Choose whether to enable Perfect Forward Secrecy (PFS) using Diffie-Hellman public-
key cryptography – see Section 18.12.3 on page 251 . Select None (the default) to disable
PFS.
• Choose Tunnel mode or Transport mode.
Cancel Click Cancel to begin configuring this screen afresh.
Advanced Setup Click Advanced Setup to configure more detailed settings of your IKE key
management.
Table 96 Edit VPN Policies
LABEL DESCRIPTION