ZyXEL Communications Prestige 662HW Series, Руководство пользователя

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Prestige 662HW Series User’s Guide
16-16 VPN Screens
Table 16-8 VPN IKE: Advanced Setup
LABEL DESCRIPTION
End Enter a port number in this field to define a port range. This port number must be greater
than that specified in the previous field. If
Remote Start Port is left at 0, End will also
remain at 0.
Phase 1
Negotiation Mode Select Main or Aggressive from the drop-down list box. Multiple SAs connecting through
a secure gateway must have the same negotiation mode.
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 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 .
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.
SA Life Time
(Seconds) Define the length of time before an IKE SA automatically renegotiates in this field. It may
range from 60 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.
Key Group 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.
Phase 2
Active Protocol Use the drop-down list box to choose from ESP or AH .