Chapter 12 IPSec VPN
P-2812HNU-51c User’s Guide
264
IP
Subnetmask
When the remote IP address type is configured to Single Address,
this field is not available.
When the remote IP address type is configured to Subnet, enter a
subnet mask on the network behind the remote IPSec router.
Protocol This field displays ESP and the P-2812HNU-51c uses ESP
(Encapsulation Security Payload) for VPN. The ESP protocol (RFC 2406)
provides encryption as well as some of the services offered by AH.
Key Exchange
Method
Select Auto(IKE) or Manual from the drop-down list box. Auto(IKE)
provides more protection so it is generally recommended. Manual is a
useful option for troubleshooting if you have problems using
Auto(IKE) key management.
Encryption
Algorithm
Select DES, 3DES, AES(aes-cbc) or ESP_NULL 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(aes-cbc) in Cipher Block
Chaining (CBC) mode uses a 128-bit key. AES is faster than 3DES.
Select ESP_NULL to set up a tunnel without encryption. When you
select ESP_NULL, you do not enter an encryption key.
Encryption Key Type 16 hexadecimal ("0-9", "A-F") characters if you select to use the
DES encryption algorithm or 48 hexadecimal characters if you use the
3DES encryption algorithm.
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.
Authentication
Key
Type 32 hexadecimal ("0-9", "A-F") characters if you select to use the
MD5 authentication algorithm or 40 hexadecimal characters if you use
the SHA1 authentication algorithm.
SPI Type a number (base 10) from 1 to 999999 for the Security Parameter
Index.
NAT Traversal Select Enable if you want to set up a VPN tunnel when there are NAT
routers between the P-2812HNU-51c and remote IPSec router. The
remote IPSec router must also enable NAT traversal, and the NAT
routers have to forward UDP port 500 packets to the remote IPSec
router behind the NAT router. Otherwise, select Disable.
Advanced IKE
Settings
Click Show Advanced Settings to display and configure more
detailed settings of your IKE key management. Otherwise, click Hide
Advanced Settings.
Enable Manual
ID Type
Select this option to specify how to identify the P-2812HNU-51c and
remote IPSec router.
Table 75 Security > IPSec VPN > IPSec Setting > Manual (continued)
LABEL DESCRIPTION
