ZyXEL Communications 792H manual IKE Phases, Two Phases to Set Up the IPSec SA

	Prestige 792H G.SHDSL Router
	Table 14-7 VPN IKE
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.
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.

14.10 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 14-4 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.

VPN Screens 14-13