ZyXEL P-792H v2 User Guide - Page 179

Remote DNS Server

Page 179 highlights

Chapter 12 VPN If the P-792H v2 has its maximum number of simultaneous IPSec tunnels connected to it and they all have keep alive enabled, then no other tunnels can take a turn connecting to the P-792H v2 because the P-792H v2 never drops the tunnels that are already connected. When there is outbound traffic with no inbound traffic, the P-792H v2 automatically drops the tunnel after two minutes. 12.9.8 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 P-792H v2 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 P-792H v2 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 82 VPN Host using Intranet DNS Server Example ISP DNS Servers 212.54.64.170 212.54.54.171 1 LAN DNS:212.54.64.170 212.54.64.171 A VPN DNS: 10.1.1.10 Internet Remote IPSec Router HQ 10.1.1.1/200 Intranet DNS 10.1.1.10 = VPN Tunnel 2 192.168.1.1/50 3 172.16.1.1/50 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. P-792H v2 User's Guide 179

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Chapter 12 VPN
P-792H v2 User’s Guide
179
If the P-792H v2 has its maximum number of simultaneous IPSec tunnels
connected to it and they all have keep alive enabled, then no other tunnels can
take a turn connecting to the P-792H v2 because the P-792H v2 never drops the
tunnels that are already connected.
When there is outbound traffic with no inbound traffic, the P-792H v2
automatically drops the tunnel after two minutes.
12.9.8
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
P-792H v2 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 P-792H v2 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 82
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.
Remote
IPSec Router
HQ
10.1.1.1/200
Intranet DNS
10.1.1.10
ISP DNS Servers
212.54.64.170
212.54.54.171
Internet
LAN
DNS:212.54.64.170
212.54.64.171
A
VPN DNS: 10.1.1.10
= VPN Tunnel
2
192.168.1.1/50
3
172.16.1.1/50
1