ZyXEL Communications P-335WT - Manual (Page 406)

P-335 Series User’s Guide
406 Chapter 39 VPN/IPSec Setup
39.4 Manual Setup
You only configure Menu 27.1.1.2 – Manual Setup when you select Manual in the Key
Management field in Menu 27.1.1 – IPSec Setup. Manual key management is useful if you
have problems with IKE key management.
SA Life Time
(Seconds)
Define the length of time before an IKE Security Association automatically renegoti-
ates 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.
Key Group You must choose a key group for phase 1 IKE setup. DH1 (default) refers to Diffie-
Hellman Group 1 a 768 bit random number. DH2 refers to Diffie-Hellman Group 2 a
1024 bit (1Kb) random number.
Phase 2
Active Protocol Press [SPACE BAR] to choose from ESP or AH and then press [ENTER]. See
earlier for a discussion of these protocols.
Encryption
Algorithm
Press [SPACE BAR] to choose from NULL, 3DES or DES and then press [ENTER].
Select NULL to set up a tunnel without encryption.
Authentication
Algorithm
Press [SPACE BAR] to choose from SHA1 or MD5 and then press [ENTER].
SA Life Time
(Seconds)
Define the length of time before an IPSec Security Association automatically
renegotiates in this field. It may range from 60 to 3,000,000 seconds (almost 35
days).
Encapsulation Press [SPACE BAR] to choose from Tunnel mode or Transport mode and then
press [ENTER]. See earlier for a discussion of these.
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. Press [SPACE BAR] and
choose from DH1 or DH2 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).
When you have completed this menu, press [ENTER] at the prompt “Press ENTER to Confirm…” to
save your configuration, or press [ESC] at any time to cancel.
Table 142 Menu 27.1.1.1 IKE Setup
FIELD DESCRIPTION