Operation Manual

Chapter 19 IPSec VPN
SBG3300-N Series User’s Guide
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Encapsulation Select which type of encapsulation the IPSec SA uses. Choices are:
Tunnel - this mode encrypts the IP header information and the data.
Transport - this mode only encrypts the data. If you set Encapsulation to
Transport, Policy (Local and Remote) is not applicable.
The Device and remote IPSec router must use the same encapsulation.
Encryption 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
AES128 - a 128-bit key with the AES encryption algorithm
AES192 - a 192-bit key with the AES encryption algorithm
AES256 - a 256-bit key with the AES encryption algorithm
The Device 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 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.
Perfect Forward
Secrecy (PFS)
Select whether or not you want to enable Perfect Forward Secrecy (PFS) and, if you do,
which Diffie-Hellman key group to use for encryption. Choices are:
DH1 - enable PFS and use a 768-bit random number
DH2 - enable PFS and use a 1024-bit random number
DH5 - enable PFS and use a 1536-bit random number
PFS changes the root key that is used to generate encryption keys for each IPSec SA.
The longer the key, the more secure the encryption, but also the longer it takes to
encrypt and decrypt information. Both routers must use the same DH key group.
Policy You cannot use a Policy (Local and Remote pair) that already exists in other enabled
IPsec rules with Site-to-Site or Site-to-Site with Dynamic Peer as the Application
Scenario. The following are two examples:
1. Example1: IPsec rule vpn1 has Local Policy set as 192.168.1.0 / 255.255.255.0
and Remote Policy as 10.10.1.0 / 255.255.255.0. You cannot use the same policy
configuration for other IPSec rules. However, you can set Local Policy as
192.168.1.0 / 255.255.255.0 and Remote Policy as 192.168.200.0 /
255.255.255.0 for a new IPSec rule vpn2.
2. Example2: IPSec rule vpn1 has Local Policy set as 192.168.1.100 and Remote
Policy as 10.10.1.33. You cannot use the same policy configuration for other IPSec
rules. However, you can set Local Policy as 192.168.1.100 and Remote Policy as
10.10.1.34 for a new IPSec rule vpn2.
Local/Remote IP
Type
Use the drop-down list box to choose Single, Range or Subnet. Select Single for a
single IP address. Select Range to enter a range of IP addresses in the Local/Remote
IP Address Start and Local/Remote IP Address End fields. Select Subnet to
specify IP addresses on a network by their subnet mask.
Table 91 VPN > IPSec VPN > Setup > Edit (continued)
LABEL DESCRIPTION