Billion Electric Company 7404V Series user manual L2TP over IPSec L2TP/IPSec VPN Connection

VoIP/(802.11g) ADSL2+ (VPN) Firewall Router

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 L2TP 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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Chapter 4: Configuration