Example: Configuring DNS proxy

As shown in Figure 44, configure Device A as the DNS proxy to forward DNS packets between the DNS client (Device B) and the DNS server at 4.1.1.1.

	IMPORTANT: By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

Before performing the following configuration, make sure that:

• Device A, the DNS server, and the host can reach each other.

• The IP addresses of the interfaces are configured as shown in Figure 44.

1. Configure the DNS server:

   The configuration might vary by DNS server. When a PC running Windows Server 2008 R2 acts as the DNS server, see "Example: Configuring dynamic domain name resolution" for configuration information.

2. Configure the DNS proxy:

   # Specify the DNS server 4.1.1.1.

   <DeviceA> system-view
   [DeviceA] dns server 4.1.1.1
   

   # Enable DNS proxy.

   [DeviceA] dns proxy enable
   

3. Configure the DNS client:

   <DeviceB> system-view
   

   # Specify the DNS server 2.1.1.2.

   [DeviceB] dns server 2.1.1.2
   

# Verify that DNS proxy on Device A functions.

[DeviceB] ping host.com
Ping host.com (3.1.1.1): 56 data bytes, press CTRL_C to break
56 bytes from 3.1.1.1: icmp_seq=0 ttl=255 time=1.000 ms
56 bytes from 3.1.1.1: icmp_seq=1 ttl=255 time=1.000 ms
56 bytes from 3.1.1.1: icmp_seq=2 ttl=255 time=1.000 ms
56 bytes from 3.1.1.1: icmp_seq=3 ttl=255 time=1.000 ms
56 bytes from 3.1.1.1: icmp_seq=4 ttl=255 time=2.000 ms

--- Ping statistics for host.com ---
5 packet(s) transmitted, 5 packet(s) received, 0.0% packet loss
round-trip min/avg/max/std-dev = 1.000/1.200/2.000/0.400 ms