Database Reference
In-Depth Information
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To achieve the high availability and load balancing, multiple redundant network interfaces
for the private network should be bonded or teamed together with OS bonding or teaming
methods prior to 11gR2 (11.2.0.2). With the introduction of Oracle HAIP in 11.2.0.2, bonding
or teaming in OS is no longer needed, as HAIP allows you to use these redundant network
interfaces directly for the private interconnect, and HAIP handles the load balance across
these network interfaces and the failover to other available network interfaces in case any
of these network interfaces is not responding. The following shows the example of the two
network interfaces, eth1 and eth2:
DEVICE=eth1
HWADDR=BC:30:5B:ED:68:C1
ONBOOT=yes
BOOTPROTO=static
TYPE=Ethernet
IPADDR=192.168.9.71
NETMASK=255.255.255.0
DEVICE=eth2
HWADDR=BC:30:5B:ED:68:C2
ONBOOT=yes
BOOTPROTO=static
TYPE=Ethernet
IPADDR=192.168.9.72
NETMASK=255.255.255.0
After you complete the configuration and save the files, you can restart the network service:
#Service network restart
Then you can use these two network interfaces, eth12 and eth2, directly for the private network configuration
during the Oracle Grid Infrastructure installation.
Establishing IP Address and Name Resolution
As you connect to a host using the hostname, Oracle database clients connect to the database using a SCAN name.
These hostnames and SCAN names need to be resolved into their associated IP addresses to allow the clients to
connect. In Oracle RAC and Clusterware, the SCAN name can be resolved into up to three SCAN IPs. For example,
the SCAN name kr720n-scan are resolved into three IPs, 172.16.9.74, 172.16.9.75, and 172.16.9.76, in the following
example. The virtual hostname is resolved into the VIP; for example, k2r720n1-vip being resolved to VIP 172.16.9.171.
The public hostname is resolved into the host IP; for example, k2r720n1 being resolved into 172.16.9.71.
The technology to resolve a name to the IP address is called name resolution. In the Oracle RAC environment,
there are two ways to implement this name resolution: 1) name resolution using DNS, and 2) name resolution using
GNS (Grid Naming Services). Oracle recommends that you establish a static hostname resolution using DNS for
all non-VIP node public hostnames. You can use either DNS or GNS for the VIP name resolution. In the following
sections, we will use two clusters as an example to show the configuration of each of these two methods and how it
works: 1) kr720n-cluster for the DNS method, and 2) owirac-cluster for the GNS method.
