D-Link DRO-250i User Manual page 78

Introduction to DRO-250i
Tunnel Type - This drop-down menu allows user to select the type of
VPN Tunnel user wants to configure. User can choose between Public,
Private, and Manual. At the time of writing of this manual, only Public
IPSec VPN tunnels were supported.
Phase 1 Proposal
Mode - User can select between Main and Aggressive modes for the
Phase 1 negotiation to establish a VPN IPSec tunnel. In the Main mode,
communication between the two endpoints of an IPSec VPN tunnel are
encrypted. In Aggressive mode, there is no encryption in the Phase 1
negotiation.
DH Group - The DH algorithm allows the Router to generate secret keys
for encryption for the Phase 1 negotiation. Group 1 generates a 768-bit
key and Group 2 generates a 1024-bit key. The same DH Group must be
used on both ends of an IPSec VPN tunnel.
IKE Life Duration - This is the life duration of phase 1 key (in seconds).
When it is expired, the two peer site should
trigger phase 1 negotiation again to set up a new phase 1 key , phase 2
negotiation also will be triggered.
IKE Hash - This drop-down menu allows user to select the algorithm that
will be used to ensure that the messages exchanged between the two IPSec
VPN tunnel endpoints have been received exactly as it was sent. In other
words, a Hash algorithm is used to generate a binary number by a
mathematical operation using the entire message. The resulting number is
called a message digest. The very same mathematical operation is
performed when the message is received, and if there has been any change
in the message in transit, the resulting message digest number will be
different and the message will be rejected. User can choose between MD5
- a 128-bit message digest, and SHA - which generates a 160-bit message
digest. User must have exactly the same IKE Hash algorithm on both ends
of a VPN tunnel.
IKE Encryption - This drop-down menu allows user to select the
encryption algorithm that will be used to encrypt the messages passed
between the VPN tunnel endpoints during the Phase 1 negotiation. User
DRO-250i User Manual
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