Netgear DGFV338 사용자 설명서

Virtual Private Networking

5-7

•

Encr. Encryption Algorithm used for the IKE SA. The default setting using the VPN Wizard is 
3DES. (This setting must match the Remote VPN.) 

•

Auth. Authentication Algorithm used for the IKE SA. The default setting using the VPN 
Wizard is SHA1. (This setting must match the Remote VPN.) 

•

DH. Diffie-Hellman Group. The Diffie-Hellman algorithm is used when exchanging keys. The 
DH Group sets the number of bits. The VPN Wizard default setting is Group 2. (This setting 
must match the Remote VPN.) 

To gain a more complete understanding of the encryption, authentication and DH algorithm 
technologies, see 

 for a link to the NETGEAR website.

You can create two types of VPN Policies. When using the VPN Wizard to create a VPN policy, 
only the Auto method is available. 

•

Manual. All settings (including the keys) for the VPN tunnel are manually input at each end 
(both VPN Endpoints). No third party server or organization is involved. 

•

Auto. Some parameters for the VPN tunnel are generated automatically by using the IKE 
(Internet Key Exchange) protocol to perform negotiations between the two VPN Endpoints 
(the Local ID Endpoint and the Remote ID Endpoint).

In addition, a CA (Certificate Authority) can also be used to perform authentication (see 

). To use a CA, each VPN Gateway must have a Certificate 

from the CA. For each Certificate, there is both a “Public Key” and a “Private Key”. The “Public 
Key” is freely distributed, and is used to encrypt data. The receiver then uses their “Private Key” to 
decrypt the data (without the Private Key, decryption is impossible). CAs can be beneficial since 
using them reduces the amount of data entry required on each VPN Endpoint. 

The VPN Policies screen allows you to add additional policies—either Auto or Manual—and to 
manage the VPN policies already created. You can edit policies, enable or disable policies, or 
delete them entirely. The rules for VPN policy use are:

1. Traffic covered by a policy will automatically be sent via a VPN tunnel. 

2. When traffic is covered by two or more policies, the first matching policy will be used. (In this 

situation, the order of the policies is important. However, if you have only one policy for each 
remote VPN Endpoint, then the policy order is not important.) 

3. The VPN tunnel is created according to the parameters in the SA (Security Association).