ZyXEL Communications Prestige 662HW Series, User Manual

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Prestige 662HW Series User’s Guide
16-12 VPN Screens
Table 16-7 VPN IKE
LABEL DESCRIPTION
Pre-Shared Key Type your pre-shared key in this field. A pre-shared key identifies a communicating
party during a phase 1 IKE negotiation. It is called "pre-shared" because you have to
share it with another party before you can communicate with them over a secure
connection.
Type from 8 to 31 case-sensitive ASCII characters or from 16 to 62 hexadecimal ("0-9",
"A-F") characters. You must precede a hexadecimal key with a "0x” (zero x), which is
not counted as part of the 16 to 62 character range for the key. For example, in
"0x0123456789ABCDEF", “0x” denotes that the key is hexadecimal and
“0123456789ABCDEF” is the key itself.
Both ends of the VPN tunnel must use the same pre-shared key. You will receive a
“PYLD_MALFORMED” (payload malformed) packet if the same pre-shared key is not
used on both ends.
Encryption Algorithm Select DES , 3DES , AES or 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 uses a 128-bit key. AES is faster
than 3DES .
Select NULL to set up a tunnel without encryption. When you select NULL , you do not
enter an encryption key.
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.
Advanced Click Advanced to configure more detailed settings of your IKE key management.
Back Click Back to return to the previous screen.
Apply Click Apply to save your changes back to the Prestige.
Cancel Click Cancel to begin configuring this screen afresh.
Delete
Click Delete to delete the current rule.
16.11 IKE Phases
There are two phases to every IKE (Internet Key Exchange) negotiation – phase 1 (Authentication)
and phase 2 (Key Exchange). A phase 1 exchange establishes an IKE SA and the second one uses that
SA to negotiate SAs for IPSec.