ZyXEL 202H 91-003-194001B User Manual

P-202H Plus v2 User’s Guide

Chapter 11 VPN Screens

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

A Security Association (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 ZyXEL Device renegotiate an IPSec SA when the SA 
lifetime expires, even if there is no traffic.

Encryption Algorithm

Select DES, 3DES or NULL from the drop-down list box. The ZyXEL Device'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 

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. Select NULL to set up a tunnel without encryption. 

When you select NULL, you do not enter an encryption key.

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 

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. 

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.

Back

Click Back to return to the previous screen.

Apply

Click Apply to save your changes back to the ZyXEL Device.

Cancel

Click Cancel to begin configuring this screen afresh.

Delete

Click Delete to remove the current rule.

Table 39   Rule Setup with Manual Key