ZyXEL Communications 2602H Series User Manual

Prestige 2602H/HW Series User’s Guide

Chapter 17 VPN Screens

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For NAT traversal to work you must:

• Use ESP security protocol (in either transport or tunnel mode).
• Use IKE keying mode.
• Enable NAT traversal on both IPSec endpoints.

In order for IPSec router A (see 

) to receive an initiating IPSec packet 

from IPSec router B, set the NAT router to forward UDP port 500 to IPSec router A.

With aggressive negotiation mode (see 

), the Prestige identifies 

incoming SAs by ID type and content since this identifying information is not encrypted. This 
enables the Prestige to distinguish between multiple rules for SAs that connect from remote 
IPSec routers that have dynamic WAN IP addresses. Telecommuters can use separate 
passwords to simultaneously connect to the Prestige from IPSec routers with dynamic IP 
addresses (see 

 for a telecommuter configuration example).

Regardless of the ID type and content configuration, the Prestige does not allow you to save 
multiple active rules with overlapping local and remote IP addresses.

With main mode (see 

), the ID type and content are encrypted to 

provide identity protection. In this case the Prestige can only distinguish between up to 12 
different incoming SAs that connect from remote IPSec routers that have dynamic WAN IP 
addresses. The Prestige can distinguish up to 12 incoming SAs because you can select between 
three encryption algorithms (DES, 3DES and AES), two authentication algorithms (MD5 and 
SHA1) and two key groups (DH1 and DH2) when you configure a VPN rule (see 

). The ID type and content act as an extra level of identification for 

incoming SAs.

The type of ID can be a domain name, an IP address or an e-mail address. The content is the IP 
address, domain name, or e-mail address.