P-2602H(W)(L)-DxA Series User’s Guide
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Chapter 17 VPN Screens
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
.
Encryption
Algorithm
This field is available when you select
ESP
in the
Active Protocol
field.
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.
Table 88
Advanced VPN Policies
LABEL
DESCRIPTION
19216811.live