Wireless ADSL2+ Modem Router DG834Gv5 User Manual
6-36
Virtual Private Networking
v1.0, March 2010
Parameters
Encryption
Algorithm
The encryption algorithm used for both IKE and IPSec. This setting
must match the setting used on the remote VPN Gateway. DES and
3DES are supported.
•
DES
. The Data Encryption Standard (DES) processes input data that
is 64 bits wide, encrypting these values using a 56-bit key. Faster but
less secure than 3DES.
•
3DES
. (Triple DES) achieves a higher level of security by encrypting
the data three times using DES with three different, unrelated keys.
Authentication
Algorithm
The authentication algorithm used for both IKE and IPSec. This setting
must match the setting used on the remote VPN Gateway. Auto, MD5,
and SHA-1 are supported. Auto negotiates with the remote VPN
endpoint and is not available in responder-only mode.
•
MD5
. 128 bits, faster but less secure.
•
SHA-1
. (default)160 bits, slower but more secure. This is the default.
Pre-shared key
The key must be entered both here and on the remote VPN Gateway.
SA Life Time
This determines the time interval before the SA (Security Association)
expires. (It will automatically be re-established as required.) While
using a short time period (or data amount) increases security, it also
degrades performance. It is common to use periods over an hour (3600
seconds) for the SA Life Time. This setting applies to both IKE and
IPSec SAs.
Enable IPSec
PFS (Perfect
Forward
Secrecy)
• If this check box is selected, security is enhanced by ensuring that the
key is changed at regular intervals. Also, even if one key is broken,
subsequent keys are no easier to break. (Each key has no
relationship to the previous key.)
• This setting applies to both IKE and IPSec SAs. When configuring the
remote endpoint to match this setting, you might have to specify the
key group used. For this device, the key group is the same as the DH
Group setting in the IKE section.
Table 6-5. VPN-Auto Policy Screen Settings (continued)
Fields and Settings
Description
