HP VPN Firewall Appliances Network Management Configuration Guide

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DNS proxy configuration example
Network requirements
When the IP address of the DNS server changes, you must configure the new IP address of the DNS
server on each device on the LAN. To simplify network management, you can use the DNS proxy
function.
As shown in Figure 148:
• S
pecify Fir
ewall as the DNS server of Device (the DNS client). Firewall acts as a DNS proxy. The IP
address of the real DNS server is 4.1.1.1.
• Configure the IP address of the DNS proxy on Device. DNS requests of Device B are forwarded to
the real DNS server through the DNS proxy.
Figure 148 Network diagram
Configuration procedure
Before performing the following configuration, assume that Device A, the DNS server, and the host are
reachable to each other and the IP addresses of the interfaces are configured as shown in Figure 148.
1. Configure the DNS server:
This configuration might vary with DNS servers. When a PC running Windows Server 2000 acts
as the DNS server, see "Dynamic domain name resolution c
onfiguration example" for related
configuration informati
on.
2. Configure the DNS proxy:
# Specify the DNS server 4.1.1.1.
<Firewall> system-view
[Firewall] dns server 4.1.1.1
# Enable DNS proxy.
[Firewall] dns proxy enable
3. Configure the DNS client:
# Enable the domain name resolution function.
<Device> system-view
[Device] dns resolve
# Specify the DNS server 2.1.1.2.
3.1.1.1/24
host.com
Device
DNS client
Firewall
DNS proxy
IP network
DNS server
2.1.1.1/24
2.1.1.2/24 1.1.1.1/24
4.1.1.1/24
Host