User's Manual

Chapter 15 IPSec VPN
NBG-460N User’s Guide
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Peer Content The configuration of the peer content depends on the peer ID type.
For IP, type the IP address of the computer with which you will make
the VPN connection. If you configure this field to 0.0.0.0 or leave it
blank, the NBG-460N will use the address in the Secure Gateway
Address field (refer to the Secure Gateway Address field
description).
For Domain Name or E-mail, type a domain name or e-mail address
by which to identify the remote IPSec router. Use up to 31 ASCII
characters including spaces, although trailing spaces are truncated.
The domain name or e-mail address is for identification purposes only
and can be any string.
It is recommended that you type an IP address other than 0.0.0.0 or
use the Domain Name or E-mail ID type in the following situations:
• When there is a NAT router between the two IPSec routers.
• When you want the NBG-460N to distinguish between VPN
connection requests that come in from remote IPSec routers with
dynamic WAN IP addresses.
IKE 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.
Encryption
Algorithm
Select which key size and encryption algorithm to use in the IKE SA.
Choices are:
DES - a 56-bit key with the DES encryption algorithm
3DES - a 168-bit key with the DES encryption algorithm
The NBG-460N and the remote IPSec router must use the same
algorithms and keys. Longer keys require more processing power,
resulting in increased latency and decreased throughput.
Authentication
Algorithm
Select which hash algorithm to use to authenticate packet data in the
IKE SA. Choices are SHA1 and MD5. SHA1 is generally considered
stronger than MD5, but it is also slower.
SA Life Time
(Seconds)
Define the length of time before an IKE SA automatically renegotiates
in this field. It may range from 180 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 Select which Diffie-Hellman key group (DHx) you want to use for
encryption keys. Choices are:
DH1 - use a 768-bit random number
DH2 - use a 1024-bit random number
Table 69 Security > VPN > General > Rule Setup: IKE (Advanced) (continued)
LABEL DESCRIPTION