SETTING UP A CONDITIONAL FORWARDER IN DNS

  A Forwarder is a DNS Server to which other DNS Server forward queries.

Types of Forwarders
  o    Standard
  o   Conditional

Conditional Forwarder: A conditional forwarder is a DNS server on a network that is used to forward DNS queries according to the DNS domain name in the query. For example, a DNS server can be configured to forward all the queries it receives for names ending with widgets.example.com to the IP address of a specific DNS server or to the IP addresses of multiple DNS servers.

Below figure shows how conditional forwarder is working.

Setting up a Conditional Forwarder:

1. Start -> Administrative Tools -> DNS

2. Right Click Conditional Forwarders -> Select New Conditional Forwarder.

3. Type the Condition and IP of appropriate DNS Server, Then Click OK

Eg: Here i have given infotech.com as my condition, If any query which is looking for infotech domain then the query will pass to 192.168.5.2 DNS Server.

SETTING UP A STANDARD FORWARDER IN DNS

  A Forwarder is a DNS Server to which other DNS Server forward queries.

          Types of Forwarders

  o    Standard

  o   Conditional

• Standard Forwarder: Standard Forwarder is a server that passes the information to other DNS Server, if it doesn't know the answer.

Below figure shows how standard forwarder is working. 

1. Start -> Administrative Tools -> DNS

2. Right Click DNS Server (BG-DC2-2k8) -> Click Properties.

3. Click Forwarder and Click Edit.

     4. Type  the appropriate IP address of DNS Server which you  want to make it as Standard DNSServer.  

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5. Apply and OK

How to Enable Scavenging in DNS Server.

                Scavenging will help you clean up old unused records in DNS. Since "clean up" really means "delete stuff" a good understanding of what you are doing and ahealthy respect for "delete stuff" will keep you out of the hot grease. Because deletion is involved there are quite a few safety valves built into scavenging that take a long time to pop. When enabling scavenging, patience is required.

              Scavenging is particularly important if you use Dynamic DNS to automatically register client host names when their IP addresses change, as is often the case when the clients receive address assignments through DHCP. Over time, client host records in a zone can become stale, and scavenging removes these records. Removing the records improves DNS server and zone transfer performance, and it ensures that host records don't conflict with older records.

In Windows Server 2008, Scavenging is disabled by default. To enable and configure on Windowss 2008 DNS Server, please do the following:

• Click Start, point to Administrative Tools, and then click DNS. This starts the DNS Server MMC snap-in.
• On the Action menu, click Properties.
• Click the Advanced tab, select “Enable automatic scavenging of stale records” and click OK.

• On the Action menu, click Set Aging/Scavenging for All Zones.

• Click “Scavenge stale resource records” check box, and then click OK. Default is “7 days”
• In the Server Aging/Scavenging Confirmation dialog box, select “Apply these settings to the existing Active Directory-integrated zones” and click OK.

This should enable scavenging stale Host and pointer records in Windows 2008 DNS server.