ZyXEL p-2802h-i1 Manual Do Utilizador

Página de 418
 Chapter 14 VPN Screens
P-2802H(W)(L)-I Series User’s Guide
191
The following figure depicts an example where three VPN tunnels are created from ZyXEL 
Device A; one to branch office 2, one to branch office 3 and another to headquarters. In order 
to access computers that use private domain names on the headquarters (HQ) network, the 
ZyXEL Device at branch office 1 uses the Intranet DNS server in headquarters. The DNS 
server feature for VPN does not work with Windows 2000 or Windows XP.
Figure 109   VPN Host using Intranet DNS Server Example
If you do not specify an Intranet DNS server on the remote network, then the VPN host must 
use IP addresses to access the computers on the remote network.
14.9  ID Type and Content
), the ZyXEL Device 
identifies incoming SAs by ID type and content since this identifying information is not 
encrypted. This enables the ZyXEL Device 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 ZyXEL Device from IPSec routers 
with dynamic IP addresses (see
 for a telecommuter configuration 
example).
Regardless of the ID type and content configuration, the ZyXEL Device 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 ZyXEL Device can only distinguish between up to 
12 different incoming SAs that connect from remote IPSec routers that have dynamic WAN IP 
addresses. The ZyXEL Device 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.