ZyXEL Communications P-335WT User Manual

P-335 Series User’s Guide

185 

Chapter 13 VPN Screens

In the web configurator, click the VPN link under Security and the SA Monitor tab. Use this 
screen to display and manage active VPN connections.

A Security  (SA) is the group of security settings related to a specific VPN tunnel. This screen 
displays active VPN connections. Use Refresh to display active VPN connections. This 
screen is read-only. The following table describes the labels in this tab.

Note: When there is outbound traffic but no inbound traffic, the SA times out 
automatically after two minutes. A tunnel with no outbound or inbound traffic is "idle" 
and does not timeout until the SA lifetime period expires. See the Keep Alive section 
to have the Prestige renegotiate an IPSec SA when the SA lifetime expires, even if 
there is no traffic.

Encryption Algorithm

Select DES or 3DES from the drop-down list box. The Prestige's encryption 

algorithm should be identical to the secure remote gateway. When DES is 

used for data communications, both sender and receiver must know the same 

secret key, which can be used to encrypt and decrypt the message. 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.

Authentication 

Algorithm

Select SHA1 or MD5 from the drop-down list box. MD5 (Message Digest 5) 

and SHA1 (Secure Hash Algorithm) 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 maximum 

security. 

Encryption Key (Only 

with ESP)

With DES, type a unique key 8 characters long. With 3DES, type a unique 

key 24 characters long. Any characters may be used, including spaces, but 

trailing spaces are truncated.

Authentication Key

Type a unique authentication key to be used by IPSec if applicable. Enter 16 

characters for MD5 authentication or 20 characters for SHA-1 authentication. 

Any characters may be used, including spaces, but trailing spaces are 

truncated.

Apply

Click Apply to save your changes back to the Prestige.

Reset

Click Reset to begin configuring this screen afresh.

Table 74   Rule Setup with Manual Key