ZyXEL Communications P-2608HWL-Dx Series - Manual (Page 240)

P-2608HWL-Dx Series User’s Guide
240 Chapter 18 IPSec VPN
18.5 Configuring Manual Key
You only configure VPN Manual Key when you select Manual in the IPSec Key Mode field
on the VPN IKE screen. This is the VPN Manual Key screen as shown next.
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.
SA Life Time
(Seconds)
Define the length of time before an IKE SA automatically renegotiates in this field.
It may range from 60 to 3,000,000 seconds (almost 35 days).
A short SA Life Time increases security by forcing the two VPN gateways to
update the encryption and authentication keys. However, every time the VPN
tunnel renegotiates, all users accessing remote resources are temporarily
disconnected.
Encapsulation Select Tunnel mode or Transport mode from the drop-down list box.
Perfect Forward
Secrecy (PFS)
Perfect Forward Secrecy (PFS) is disabled (NONE) by default in phase 2 IPSec
SA setup. This allows faster IPSec setup, but is not so secure. Choose DH1 or
DH2 from the drop-down list box to enable PFS. DH1 refers to Diffie-Hellman
Group 1 a 768 bit random number. DH2 refers to Diffie-Hellman Group 2 a 1024
bit (1Kb) random number (more secure, yet slower).
Back Click Back to return to the previous screen.
Apply Click Apply to save your changes back to the ZyXEL Device and return to the
VPN-IKE screen.
Cancel Click Cancel to clear your changes.
Table 85 Advanced VPN Policies
LABEL DESCRIPTION