D-Link DFL-260E User Manual page 402

9.3.2. Internet Key Exchange (IKE)
PFS DH Group
IPsec DH Group
IPsec Encryption
IPsec Authentication
IPsec Lifetime
Diffie-Hellman Groups
Diffie-Hellman (DH) is a cryptographic protocol that allows two parties that have no prior
knowledge of each other to establish a shared secret key over an insecure communications channel
phase-1 SA every time a phase-2 negotiation has been
finished, making sure no more than one phase-2 negotiation is
encrypted using the same key.
PFS is generally not needed, since it is very unlikely that any
encryption or authentication keys will be compromised.
This specifies the Diffie-Hellman group to use with PFS. The
available DH groups are discussed below.
This specifies the Diffie-Hellman group to use for IPsec
communication. The available DH groups are discussed
below in the section titled Diffie-Hellman Groups.
The encryption algorithm that will be used on the protected
IPsec traffic.
This is not needed when AH is used, or when ESP is used
without encryption.
The algorithms supported by NetDefend Firewall VPNs are:
• AES
• Blowfish
• Twofish
• Cast128
• 3DES
• DES
This specifies the authentication algorithm used on the
protected traffic.
This is not used when ESP is used without authentication,
although it is not recommended to use ESP without
authentication.
The algorithms supported by NetDefend Firewall VPNs are:
• SHA1
• MD5
This is the lifetime of the VPN connection. It is specified in
both time (seconds) and data amount (kilobytes). Whenever
either of these values is exceeded, a re-key will be initiated,
providing new IPsec encryption and authentication session
keys. If the VPN connection has not been used during the last
re-key period, the connection will be terminated, and
re-opened from scratch when the connection is needed again.
This value must be set lower than the IKE lifetime.
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Chapter 9. VPN