ZyXEL Communications 650 Series - Manual (Page 185)

Prestige 650 Series User’s Guide
VPN Screens 16-13
Table 16-7 VPN IKE
LABEL DESCRIPTION
Authentication
Algorithm
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.
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.
16.10 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 16-4 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.