Linux: How to Configure the DNS Server for 11gR2 SCAN

(Doc ID 1107295.1)

Last updated on SEPTEMBER 27, 2017

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.1 to 12.1.0.2 [Release 11.2 to 12.1]
Generic Linux
The commands listed in this Note tested at Red Hat Enterprise Server 5 Update 2. For the other Linux enviroments it should be similar.

Goal

This note explains how to configure the DNS to accommodate SCAN-VIP. In most cases this task is carried out by the Network Administrator, but awareness of these steps can be very useful for assisting your network administrator in configuring DNS properly for SCAN and/or provide the ability to configure DNS in a sandbox enviroment.

If there is no separate DNS Server box available for your test case, you can have one of the cluster nodes (example: rac1 or rac2) also acting as the DNS server. Note, however, that using one of your cluster nodes as your DNS server is not supported in production.

This note will demonstrate how to prepare the SCAN-IP on a Linux DNS Server

When installing Grid Infrastructure, there are 2 options:

1. Configure GNS and let it handle name resolution
OR
2. Choose not to configure GNS and configure each Node and SCAN name with IP addresses defined in DNS

For the purpose of this note, we will not involve GNS (see <Note:946452.1> for how to configure GNS).

The three nodes involved in this case are:  rac1, rac2, and dns1.  The domain is:  testenv.com

Node Name           Public IP            Private IP              VIP IP          
rac1.testenv.com     17.17.0.1            172.168.2.1           192.168.2.221
rac2.testenv.com     17.17.0.2            172.168.2.2           192.168.2.222
dns1.testenv.com     17.17.0.35            

The target scan-vip name is: rac-scan  
rac-scan will be configued with the following 3 IP addresses:  192.168.2.11, 192.168.2.12, 192.168.2.13

Solution

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