ZyXEL Communications ZyWall P1 User Manual page 140

Table 43 VPN Rules (IKE): Gateway Policy (continued)
LABEL
Authenticated by
User Name
Password
IKE Proposal
Negotiation Mode
Encryption
Algorithm
Authentication
Algorithm
SA Life Time
(Seconds)
Key Group
Enable Multiple
Proposals
Associated
Network Policy
#
Chapter 9 VPN Screens
DESCRIPTION
Select XAUTH to to have the remote IPSec router authenticate user(s) that
request this VPN connection.
Note: You must also configure extended authentication on the
remote IPsec router.
Select ZyWALL to have your ZyWALL authenticate user(s) using a username and
password when initiating this VPN connection. Select this option if the remote
IPSec router is not configured to authenticate VPN user or does not have the
extended authentication function.
Select None to have the ZyWALL automatically try to establish a VPN connection
when packets are sent. No user authentication is required.
Enter a user name to authenticate the VPN user. The user name can be up to 31
case-sensitive ASCII characters, but spaces are not allowed.
Enter the corresponding password for the above user name. The password can
be up to 31 case-sensitive ASCII characters, but spaces are not allowed.
Select Main or Aggressive from the drop-down list box. Multiple SAs connecting
through a secure gateway must have the same negotiation mode.
Select DES, 3DES or AES from the drop-down list box.
When you use one of these encryption algorithms for data communications, both
the sending device and the receiving device must use the same secret key, which
can be used to encrypt and decrypt the message or to generate and verify a
message authentication code. The DES encryption algorithm uses a 56-bit key.
Triple DES (3DES) is a variation on DES that uses a 168-bit key. As a result,
3DES is more secure than DES. It also requires more processing power, resulting
in increased latency and decreased throughput. This implementation of AES uses
a 128-bit key. AES is faster than 3DES.
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.
Define the length of time before an IKE SA automatically renegotiates in this field.
It may range from 180 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.
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.
Select this check box to allow the ZyWALL to use any of its phase 1 or phase 2
encryption and authentication algorithms when negotiating an IPSec SA.
Clear this check box to have the ZyWALL use only the phase 1 or phase 2
encryption and authentication algorithms configured below when negotiating an
IPSec SA.
The following table shows the policy(ies) you configure for this rule.
To add a VPN policy, click the add policy icon (
(IKE) screen.
This field displays the policy index number.
ZyWALL P1 User's Guide
) in the main VPN Rules
139