ZyXEL 202H 91-003-194003B User Manual

P-202H Plus v2 User’s Guide

Chapter 33 VPN/IPSec Setup

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You only configure Menu 27.1.1.2 – Manual Setup when you select Manual in the Key 
Management field in Menu 27.1.1 – IPSec Setup. Manual key management is useful if you 
have problems with IKE key management.

This field is a combination of mode and security protocols used for the VPN. See the Web 
Configurator part on VPN for more information on these parameters. 

SA Life Time 

(Seconds)

Define the length of time before an IKE Security  automatically renegotiates in this 

field. It may range from 60 to 3,000,000 seconds (almost 35 days).
A short SA Life Time increases security by forcing the two VPN gateways to update 

the encryption and authentication keys. However, every time the VPN tunnel 

renegotiates, all users accessing remote resources are temporarily disconnected. 

Key Group

You must choose a key group for phase 1 IKE setup. DH1 (default) refers to Diffie-

Hellman Group 1 a 768 bit random number. DH2 refers to Diffie-Hellman Group 2 a 

1024 bit (1Kb) random number. 

Phase 2

Active Protocol

Press [SPACE BAR] to choose from ESP or AH and then press [ENTER]. See 

earlier for a discussion of these protocols.

Encryption 

Algorithm

Press [SPACE BAR] to choose from NULL, 3DES or DES and then press [ENTER]. 

Select NULL to set up a tunnel without encryption.

Authentication 

Algorithm

Press [SPACE BAR] to choose from SHA1 or MD5 and then press [ENTER].

SA Life Time 

(Seconds)

Define the length of time before an IPSec Security  automatically renegotiates in this 

field. It may range from 60 to 3,000,000 seconds (almost 35 days).

Encapsulation

Press [SPACE BAR] to choose from Tunnel mode or Transport mode and then 

press [ENTER]. See earlier for a discussion of these.

Perfect Forward 

Secrecy (PFS)

Perfect Forward Secrecy (PFS) is disabled (None) by default in phase 2 IPSec SA 

setup. This allows faster IPSec setup, but is not so secure. Press [SPACE BAR] and 

choose from DH1 or DH2 to enable PFS. DH1 refers to Diffie-Hellman Group 1 a 768 

bit random number. DH2 refers to Diffie-Hellman Group 2 a 1024 bit (1Kb) random 

number (more secure, yet slower). 

When you have completed this menu, press [ENTER] at the prompt “Press ENTER to Confirm…” to 

save your configuration, or press [ESC] at any time to cancel.

Table 102   Menu 27.1.1.1 IKE Setup

Table 103   Active Protocol: Encapsulation and Security Protocol

Tunnel

ESP

Transport

AH