ZyXEL VSG1432-B101 User Guide - Page 259

IKE Phases

Page 259 highlights

Chapter 21 IPSec 21.4.3 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 122 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 an encryption algorithm. • Choose an authentication algorithm • Choose a Diffie-Hellman public-key cryptography key group. • Set the IPSec SA lifetime. This field allows you to determine how long the IPSec SA should stay up before it times out. The ZyXEL Device automatically renegotiates the IPSec SA if there is traffic when the IPSec SA lifetime period expires. If an IPSec SA times out, then the IPSec router must renegotiate the SA the next time someone attempts to send traffic. VSG1432-B101 Series User's Guide 259

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Chapter 21 IPSec
VSG1432-B101 Series User’s Guide
259
21.4.3
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 122
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 an encryption algorithm.
Choose an authentication algorithm
Choose a Diffie-Hellman public-key cryptography key group
.
Set the IPSec SA lifetime. This field allows you to determine how long the IPSec
SA should stay up before it times out. The ZyXEL Device automatically
renegotiates the IPSec SA if there is traffic when the IPSec SA lifetime period
expires. If an IPSec SA times out, then the IPSec router must renegotiate the
SA the next time someone attempts to send traffic.