2.7.1 IP Address Requirements
Before starting the installation, you must have the following IP addresses available for each node:
-
An IP address with an associated network name registered in the domain name service (DNS) for the public interface. If you do not have an available DNS, then record the network name and IP address in the system hosts file,
/etc/hosts. -
One virtual IP (VIP) address with an associated network name registered in DNS. If you do not have an available DNS, then record the network name and VIP address in the system hosts file,
/etc/hosts. Select an address for your VIP that meets the following requirements:-
The IP address and network name are currently unused
-
The VIP is on the same subnet as your public interface
Before installation, check that the default gateway can be accessed by a
pingcommand. During installation, OUI uses thepingcommand to ensure that the VIP is reachable. To find the default gateway, use theroutecommand, as described in your operating system's help utility. After installation, configure clients to use either the VIP address, or the network name associated with the VIP. If a node fails, then the node's virtual IP address fails over to another node. -
-
A private IP address with a host name for each private interface
Oracle recommends that you use private network IP addresses for these interfaces (for example: 10.*.*.* or 192.168.*.*). Use the
/etc/hostsfile on each node to associate private network names with private IP addresses.
For example, with a two node cluster where each node has one public and one private interface, you might have the configuration shown in the following table for your network interfaces, where the hosts file is /etc/hosts:
| Node | Interface Name | Type | IP Address | Registered In |
|---|---|---|---|---|
| rac1 | rac1 | Public | 143.46.43.100 | DNS (if available, else the hosts file) |
| rac1 | rac1-vip | Virtual | 143.46.43.104 | DNS (if available, else the hosts file) |
| rac1 | rac1-priv | Private | 10.0.0.1 | Hosts file |
| rac2 | rac2 | Public | 143.46.43.101 | DNS (if available, else the hosts file) |
| rac2 | rac2-vip | Virtual | 143.46.43.105 | DNS (if available, else the hosts file) |
| rac2 | rac2-priv | Private | 10.0.0.2 | Hosts file |
To enable VIP failover, the configuration shown in the preceding table defines the public and VIP addresses of both nodes on the same subnet, 143.46.43. When a node or interconnect fails, then the associated VIP is relocated to the surviving instance, enabling fast notification of the failure to the clients connecting through that VIP. If the application and client are configured with transparent application failover options, then the client is reconnected to the surviving instance.
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