Billion BiPAC 8700VAX(L)-1600, Руководство пользователя

Страница: 231 / 327

226
IPSec for L2TP
Connection Name:
A given name for the connection, but it should contain no spaces (e.g.
“connection-to-office”).
WAN Interface:
Select the set interface for the IPSec tunnel.
Remote Security Gateway:
Input the IP of remote security gateway.
Key Exchange Method:
Displays key exchange method.
Pre-Shared Key:
This is for the Internet Key Exchange (IKE) protocol, a string from 1 to 32
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).
Encryption Algorithm:
Select the encryption algorithm from the drop-down menu. There are
several options: 3DES and AES (128, 192 and 256). 3DES and AES are more powerful but
increase latency.
L
DES:
Stands for Triple Data Encryption Standard, it uses 56 bits as an encryption method.
L
3DES:
Stands for Triple Data Encryption Standard, it uses 168 (56*3) bits as an encryption
method.
L
AES:
Stands for Advanced Encryption Standards, you can use 128, 192 or 256 bits as
encryption method.
Integrity Algorithm:
Authentication establishes the integrity of the datagram and ensures it is not
tampered with in transmit. There are 2 options: Message Digest 5 (MD5) and Secure Hash
Algorithm (SHA1). SHA1 is more resistant to brute-force attacks than MD5. However, it is slower.
L
MD5:
A one-way hashing algorithm that produces a 128 − bit hash.
L
SHA1:
A one-way hashing algorithm that produces a 160 − bit hash.
DH Group:
It 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). MODP stands for Modular
Exponentiation Groups.
IPSec Lifetime:
Specify the number of minutes that IPSec will stay active before new encryption
and authentication key will be exchanged. Enter a value to negotiate and establish secure
authentication. Default is 60 minutes (3600 seconds). A short time increases security by forcing the
two parties to update the keys. However, every time when the VPN tunnel re- negotiates, access
through the tunnel will be temporarily disconnected.