ZyXEL Communications P-334 User Manual

Prestige 334 User’s Guide

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Chapter 15 VPN Screens

Having everyone use the same pre-shared key may create a vulnerability. If the pre-shared key 
is compromised, all of the VPN connections using that VPN rule are at risk. A recommended 
alternative is to use a different VPN rule for each telecommuter and identify them by unique 
IDs (see

)..

Figure 70   Telecommuters Sharing One VPN Rule Example

With aggressive negotiation mode (see section Negotiation Mode), the Prestige can use the ID 
types and contents to distinguish between VPN rules. Telecommuters can each use a separate 
VPN rule to simultaneously access a Prestige at headquarters. They can use different IPSec 
parameters (including the pre-shared key) and the local IP addresses (or ranges of addresses) 
can overlap.

Table 56   Telecommuter and Headquarters Configuration Example

My IP Address: 

0.0.0.0 (dynamic IP address 

assigned by the ISP)

Public static IP address

IP Address:

Public static IP address or domain 

name.

0.0.0.0        With this IP address only the 

telecommuter can initiate the IPSec tunnel.