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DNS is NOT required to run RAC
If you are going to use DNS it makes sense to have all 2 public, 2 private, 2 VIP, 3 scan ip (all 9 of them) in the DNS.
it depends. If you decide to use GNS then no but it you want to do manual configuration of the oracle network portion then yes. (Personally I would suggest do so just as a fallback but that's just me).
the following from the install guide explains it best:
1.2.4 Overview of Network Connection Requirements
The following is an overview of network configuration requirements for Grid Naming Service (GNS) in a Grid Plug and Play configuration, and manual network configuration. Network administrators and system administrators can refer to the Preinstallation chapter in Oracle Grid Infrastructure Installation Guide for your platform for detailed configuration information.
The network configuration for Oracle Clusterware and Oracle RAC requires several addresses. The following is a list of those addresses:
GNS virtual IP address (GNS installations only): A static IP address configured in the GNS. The GNS virtual IP listener forwards queries to nodes in the subdomain on the cluster managed by GNS.
Within the subdomain, the GNS uses multicast Domain Name Service (mDNS) to enable the cluster to map hostnames and IP addresses dynamically as nodes are added and removed from the cluster, without requiring additional host configuration in the DNS.
To enable GNS, you must have your network administrator provide a set of IP addresses for a subdomain assigned to the cluster (for example, grid.example.com), and forward DNS requests for that subdomain to the GNS virtual IP address for the cluster, which GNS will serve.
Single Client Access Name (SCAN): A domain name that resolves to all the addresses allocated for the SCAN. Oracle recommends that you allocate three addresses to the SCAN. During Oracle Grid Infrastructure installation, listeners are created for each of the SCAN addresses, and Oracle Clusterware controls which server responds to a SCAN address request.
For high availability, you should provide at least three IP addresses in the DNS to use for SCAN mapping for high availability. A SCAN domain name must be unique within your corporate network.
Virtual IP address: A public internet protocol (IP) address for each node, to be used as the Virtual IP address (VIP) for client connections. If a node fails, then Oracle Clusterware fails over the VIP address to an available node.
During installation, if you do not use Grid Naming Service (which provides the VIP automatically), you provide VIP addresses. The VIP for each node is associated with the same interface name on every node that is part of your cluster. If you have a domain name server (DNS), then your network administrator should register the host names for the VIP with the DNS, so that it is resolvable from any client, as well as the cluster nodes. The VIP should not be in use at the time of the installation, because this is an IP address that Oracle Clusterware manages.
Public IP address: A public host name address for each node, assigned by GNS, or assigned by the system administrator during initial system configuration for manual configurations. The public IP address name must be resolvable to the hostname. Register both the public IP and the VIP address with the DNS. If you do not have a DNS, then you must make sure that both public IP addresses are in the node /etc/hosts file (for all cluster nodes).
Private IP address: A private IP address for each node to serve as the private interconnect address, dedicated exclusively to internode cluster communication. GNS configures the address automatically. If you select manual configuration, then you must ensure that the following is true for each private IP address:
It must be separate from the public network
It must be accessible on the same network interface on each node
It must be connected to a network switch between the nodes for the private network; crosscable interconnects are not supported
The private interconnect is used for internode communication by both Oracle Clusterware and Oracle RAC. If you use manual configuration, then the private IP address must be available in each node's /etc/hosts file. Oracle recommends that it is configured on a dedicated switch (or switches) that are not connected to anything other than the nodes in the same cluster.
All host names must conform to the RFC 952 standard, which permits alphanumeric characters. Host names using underscores ("_") are not allowed.
do all the IP needs to be in a DNS server or just the 3 IP related to the scan ?You should have static IPs as you were having for RAC but for scan, you can use DSN (even it is not mandatory here also)
So do i need to put in 2 public, 2 private, 2 VIP, 3 scan ip (all 9 of them) in the DNS or just the 3 scan ip ???Just 3 scan IPs from DNS which will be configured there and will be provided to clients, all other should be statically asigned to RAC nodes.
Edited by: Salman Qureshi on Aug 27, 2010 10:22 PM
It is not necessary to configure SCAN IP's using DNS.
We can add /etc/hosts file if only one IP is configured with SCAN. In this case we don't see round robin as we have configured only one IP for scan.
Otherwise we can use DNS for configuring SCAN for 3 IP's.
why resurrect 30+ month old thread as your FIRST post?
In DNS Server you have to configure zone with 3 SCAN IP and 2 VIP.