Billion Electric Company BiPAC 7402G - Manual (Page 102)

802.11g ADSL2+ VPN Firewall Router
Chapter 4: Configuration
Idle Time : Auto-disconnect the VPN connection when there is no activity on the connection for a
predetermined period of time. 0 means this connection is always on.
Active as default route : Commonly used by the Dial-out connection which all packets will route through
the VPN tunnel to the Internet; therefore, active the function may degrade the Internet performance.
Click Apply after changing settings.
L2TP over IPSec (L2TP/IPSec) VPN Connection
IPSec: Enable for enhancing your LT2P VPN security.
Authentication: Authentication establishes the integrity of the datagram and ensures it is not tampered
with in transmit. There are three options, Message Digest 5 (MD5), Secure Hash Algorithm (SHA1) or
NONE
. SHA1 is more resistant to brute-force attacks than MD5, however it is slower.
MD5:
A one-way hashing algorithm that produces a 128−bit hash.
SHA1: A one-way hashing algorithm that produces a 160−bit hash.
Encryption:
Select the encryption method from the pull-down menu. There are four options, DES, 3DES,
AES and NONE. NONE means it is a tunnel only with no encryption. 3DES and AES are more powerful
but increase latency.
DES:
Stands for Data Encryption Standard, it uses 56 bits as an encryption method.
3DES: Stands for Triple Data Encryption Standard, it uses 168 (56*3) bits as an encryption
method.
AES: Stands for Advanced Encryption Standards, it uses 128 bits as an encryption method.
Perfect Forward Secrecy:
Choose whether to enable PFS using Diffie-Hellman public-key cryptography
to change encryption keys during the second phase of VPN negotiation. This function will provide better
security, but extends the VPN negotiation time. Diffie-Hellman is a public-key cryptography protocol that
allows two parties to establish a shared secret over an unsecured communication channel (i.e. over the
Internet). There are three modes, MODP 768-bit, MODP 1024-bit and MODP 1536-bit. MODP stands for
Modular Exponentiation Groups.
Pre-shared Key:
This is for the Internet Key Exchange (IKE) protocol, a string from 4 to 128 characters.
Both sides should use the same key. IKE is used to establish a shared security policy and authenticated
keys for services (such as IPSec) that require a key. Before any IPSec traffic can be passed, each router
must be able to verify the identity of its peer. This can be done by manually entering the pre-shared key
into both sides (router or hosts).
Remote Host Name (Optional): Enter hostname of remote VPN device. It is a tunnel identifier from the
Remote VPN device matches with the Remote hostname provided. If remote hostname matches, tunnel
will be connected; otherwise, it will be dropped.
Cautious: This is only when the router performs as a VPN server. This option should be used by advanced users
only.
Local Host Name (Optional): Enter hostname of Local VPN device that is connected / establishes a
VPN tunnel. As default, Router’s default Hostname is home.gateway.
Tunnel Authentication: This enables router to authenticate both the L2TP remote and L2TP host. This
is only valid when L2TP remote supports this feature.
Secret: The secure password length should be 16 characters which may include numbers and
characters. Click Apply after changing settings.
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