Configuring DNS proxy caching

To configure Content Gateway as a DNS proxy cache:

  • Add a remap rule in the ipnat.conf file.
  • Enable the DNS proxy option and specify the port that Content Gateway will use for DNS proxy traffic.
  • Configure your layer 4 switch or WCCP router to send DNS traffic on port 53 to Content Gateway.
Important: You can use the DNS proxy caching option only with a layer 4 switch or a Cisco router running WCCP v2.

In the Content Gateway manager:

Steps

  1. Go to the Configure > Networking > ARM > General tab.
  2. Under Redirection Rules, click Edit File to open the file editor for the ipnat.conf file.
  3. Enter the following information:
    1. Enter the Content Gateway Ethernet Interface to which client DNS requests are routed. For example, eth0.
    2. In the Connection Type drop-down list, select udp.
    3. In the Destination IP field, enter 0.0.0.0 to accept DNS requests from all clients.
    4. (Optional) In the Destination CIDR field, enter the CIDR mask value. If you have specified 0.0.0.0 in the Destination IP field, enter 0 here.
    5. In the Destination Port field, enter the port on which DNS requests are sent to Content Gateway (53, by default).
    6. In the Redirected Destination IP field, enter the IP address of Content Gateway.
    7. In the Redirected Destination Port field, enter the port that Content Gateway uses to communicate with the DNS server (5353, by default).
    8. In the User Protocol drop-down list, select dns.
  4. Click Add, then click Apply, and then click Close. Postpone the prompted restart until step 8.
  5. Go to the My Proxy > Basic page.
  6. Under Features > Networking, enable DNS Proxy and click Apply. Postpone the prompted restart until step 8.
  7. Go to the Networking > DNS Proxy page.
  8. Enter the DNS Proxy Port (5353, by default).
  9. Click Apply and restart Content Gateway.
  10. Configure your layer 4 switch or WCCP v2 router to send DNS traffic to the Content Gateway DNS port (53, by default).