ZyXEL Communications P-661H-61, Manual

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Chapter 16 VPN
P-661HNU-Fx User’s Guide
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16.4 Configuring Advanced Settings
Click Advanced Setup in the VPN Setup-Edit screen to open this screen.
Figure 99 Security > VPN > Setup > Edit > Advanced Setup
The following table describes the fields in this screen.
Table 59 Security > VPN > Setup > Edit > Advanced Setup
LABEL DESCRIPTION
Advanced Setup
Phase 1
Encryption
Algorithm
Select 3DES, AES128 or AES256 from the drop-down list box.
When you use one of these encryption algorithms for data
communications, both the sending device and the receiving device
must use the same secret key, which can be used to encrypt and
decrypt the message or to generate and verify a message
authentication code. The DES encryption algorithm uses a 56-bit key.
Triple DES (3DES) is a variation on DES that uses a 168-bit key. As a
result, 3DES is more secure than DES. It also requires more
processing power, resulting in increased latency and decreased
throughput.
This implementation of AES uses a 128-bit key and a 256-bit key. AES
is faster than 3DES.
Authentication
Algorithm Select MD5, SHA1, SHA2-256 or SHA2-512 from the drop-down list
box. MD5 (Message Digest 5) and SHA1 (Secure Hash Algorithm) and
SHA2 are hash algorithms used to authenticate packet data. The
SHA1 algorithm is generally considered stronger than MD5, but is
slower. Select MD5 for minimal security and SHA-1 for more security.
SHA2-256 or SHA2-512 are part of the SHA2 set of cryptographic
functions and they are considered even more secure than MD5 and
SHA1.