Vpn Rule Setup (Manual) - ZyXEL Communications NBG-4600N User Manual

Table 69 Security > VPN > General > Rule Setup: IKE (Advanced) (continued)
LABEL
Perfect Forward
Secrecy (PFS)
Basic...
Apply
Reset
Cancel

15.4.3 VPN Rule Setup (Manual)

Use this screen to configure VPN rules (tunnels) that use manual keys. Manual key
management is useful if you have problems with IKE key management.
Select Manual in the IPSec Keying Mode field on the Rule Setup screen to
open the screen as shown in
15.4.3.1 IPSec SA Using Manual Keys
You might set up an IPSec SA using manual keys when you want to establish a
VPN tunnel quickly, for example, for troubleshooting. You should only do this as a
temporary solution, however, because it is not as secure as a regular IPSec SA.
In IPSec SAs using manual keys, the NBG-460N and remote IPSec router do not
establish an IKE SA. They only establish an IPSec SA. As a result, an IPSec SA
using manual keys has some characteristics of IKE SA and some characteristics of
IPSec SA. There are also some differences between IPSec SA using manual keys
and other types of SA.
15.4.3.2 IPSec SA Proposal Using Manual Keys
In IPSec SA using manual keys, you can only specify one encryption algorithm and
one authentication algorithm. There is no DH key exchange, so you have to
provide the encryption key and the authentication key the NBG-460N and remote
IPSec router use.
Note: The NBG-460N and remote IPSec router must use the same encryption key
and authentication key.
NBG-460N User's Guide
DESCRIPTION
Select whether or not you want to enable Perfect Forward Secrecy
(PFS) and, if you do, which Diffie-Hellman key group to use for
encryption. Choices are:
None - disable PFS
DH1 - enable PFS and use a 768-bit random number
DH2 - enable PFS and use a 1024-bit random number
PFS changes the root key that is used to generate encryption keys for
each IPSec SA. It is more secure but takes more time.
Click Basic... to go to the previous VPN configuration screen.
Click Apply to save the changes.
Click Reset to begin configuring this screen afresh.
Click Cancel to exit the screen without making any changes.
Figure 134 on page
Chapter 15 IPSec VPN
214.
213