Monday, 9 July 2012

Configure a SCAN IP using DNS for Oracle Grid Infrastructure (Oracle 11gR2)


The SCAN  IP addresses must be on the same subnet as your public network in the cluster. The name must be 15 characters or less in length,not including the domain, and must be resolvable without the domain suffix (for example: “coltdb01-scan’ must be resolvable as opposed to “coltdb01-scan.example.com”).

Follow the steps to configure the SCAN IPs using DNS


1) To identify your DNS server in RHEL 



   [root@coltdb02 ~]# cat /etc/resolv.conf



2) Connect to the DNS server open the DNS administrator window
   
   Start -> Run -> dnsmgmt.msc

3) Right Click on the Domain name and select 'New Host'. Provide the Name and ip as below.



4) Repeat this step for 3 times.You have to create a single name that resolves to 3 IP
   addresses using a round-robin algorithm.

5) You can check the SCAN configuration in DNS using “nslookup”. If your DNS is set up to provide round-robin access to the IPs resolved by the SCAN entry, then run the “nslookup” command at least twice to see the round-robin algorithm work. The result should be that each time, the “nslookup” would return a set of 3 IPs in a different order.

[root@coltdb01 ~]# nslookup coltdb01-scan
Server:         10.91.119.134
Address:        10.91.119.134#53

Name:   coltdb01-scan.example.com
Address: 10.91.119.167
Name:   coltdb01-scan.example.com
Address: 10.91.119.166
Name:   coltdb01-scan.example.com
Address: 10.91.119.168

[root@coltdb01 ~]# nslookup coltdb01-scan
Server:         10.91.119.134
Address:        10.91.119.134#53

Name:   coltdb01-scan.example.com
Address: 10.91.119.166
Name:   coltdb01-scan.example.com
Address: 10.91.119.168
Name:   coltdb01-scan.example.com
Address: 10.91.119.167

4 comments:

  1. Hi Senthil,

    If i wanted to use SCAN with GNS then what are the steps to be configured in the windows 2008 DNS & DHCP server ? Can you please provide these steps with screenshots ?

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  2. Hi Senthil,

    Thanks. I am very much stuck with the GNS configuration. Can you send the steps to configure the windows 2008 DNS & DHCP server for the GNS feature to my mail id ashokdb2k@gmail.com


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  3. I have posted the steps using GNS, let me know, if that was useful

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