ZyXEL Communications P-2602HW(L) Series - Manual (Page 227)

P-2602H(W)(L)-DxA Series User’s Guide
Chapter 17 VPN Screens 227
Y* - This is supported in the ZyXEL Device if you enable NAT traversal.
17.8 Remote DNS Server
In cases where you want to use domain names to access Intranet servers on a remote network
that has a DNS server, you must identify that DNS server. You cannot use DNS servers on the
LAN or from the ISP since these DNS servers cannot resolve domain names to private IP
addresses on the remote network
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 123 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.
17.9 ID Type and Content
With aggressive negotiation mode (see Section 17.12.1 on page 235 ), 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
Section 17.18 on page 244 for a telecommuter configuration
example).