ZyXEL Communications ZyWALL 110 Series, User Manual, Page: 293 / 562

Chapter 20 IPSec VPN
ZyWALL 110/310/1100 Series User’s Guide
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This table describes labels specific to manual key configuration. See Section 20.2 on page 285 for
descriptions of the other fields.
Table 108
Configuration > VPN > IPSec VPN > VPN Connection > Add > Manual Key
LABEL DESCRIPTION
Manual Key
My Address Type the IP address of the ZyWALL in the IPSec SA.
Secure Gateway
Address
Type the IP address of the remote IPSec router in the IPSec SA.
SPI Type a unique SPI (Security Parameter Index) between 256 and 4095. The SPI is used
to identify the ZyWALL during authentication.
The ZyWALL and remote IPSec router must use the same SPI.
Encapsulation
Mode
Select which type of encapsulation the IPSec SA uses. Choices are
Tunnel - this mode encrypts the IP header information and the data
Transport - this mode only encrypts the data. You should only select this if the IPSec
SA is used for communication between the ZyWALL and remote IPSec router.
If you select Transport mode, the ZyWALL automatically switches to Tunnel mode if
the IPSec SA is not used for communication between the ZyWALL and remote IPSec
router. In this case, the ZyWALL generates a log message for this change.
The ZyWALL and remote IPSec router must use the same encapsulation.
Active Protocol Select which protocol you want to use in the IPSec SA. Choices are:
AH (RFC 2402) - provides integrity, authentication, sequence integrity (replay
resistance), and non-repudiation but not encryption. If you select AH, you must select
an Authentication Algorithm.
ESP (RFC 2406) - provides encryption and the same services offered by AH, but its
authentication is weaker. If you select ESP, you must select an Encryption Algorithm
and Authentication Algorithm.
The ZyWALL and remote IPSec router must use the same protocol.
Encryption
Algorithm
This field is applicable when the Active Protocol is ESP. Select which key size and
encryption algorithm to use in the IPSec SA. Choices are:
NULL - no encryption key or algorithm
DES - a 56-bit key with the DES encryption algorithm
3DES - a 168-bit key with the DES encryption algorithm
AES128 - a 128-bit key with the AES encryption algorithm
AES192 - a 192-bit key with the AES encryption algorithm
AES256 - a 256-bit key with the AES encryption algorithm
The ZyWALL and the remote IPSec router must use the same algorithm and key. Longer
keys require more processing power, resulting in increased latency and decreased
throughput.
Authentication
Algorithm
Select which hash algorithm to use to authenticate packet data in the IPSec SA.
Choices are SHA1, SHA256, SHA512 and MD5. SHA is generally considered stronger
than MD5, but it is also slower.
The ZyWALL and remote IPSec router must use the same algorithm.