Changing a Network Interface

You can change a network interface and its associated subnet address using the following procedure. You must perform this change on all nodes in the cluster.

This procedure changes the network interface and IP address on each node in the cluster used previously by Oracle Clusterware and Oracle Database.

Caution:

The interface that the Oracle RAC (RDBMS) interconnect uses must be the same interface that Oracle Clusterware uses with the host name. Do not configure the private interconnect for Oracle RAC on a separate interface that is not monitored by Oracle Clusterware.

Ensure that Oracle Clusterware is running on all of the cluster nodes by running the following command:
```
$ olsnodes -s
```
The command returns output similar to the following, showing that Oracle Clusterware is running on all of the nodes in the cluster:
```
./olsnodes -s
myclustera Active
myclusterc Active
myclusterb Active
```
Ensure that the replacement interface is configured and operational in the operating system on all of the nodes. Use the ifconfig command (or ipconfig on Windows) for your platform. For example, on Linux, use:
```
$ /sbin/ifconfig..
```
Add the new interface to the cluster as follows, providing the name of the new interface and the subnet address, using the following command:
```
$ oifcfg setif -global if_name/subnet:cluster_interconnect
```
You can use wildcards with the interface name. For example, oifcfg setif -global "eth*/192.168.0.0:cluster_interconnect is valid syntax. However, be careful to avoid ambiguity with other addresses or masks used with other cluster interfaces. If you use wildcards, then you see a warning similar to the following:
```
eth*/192.168.0.0 global cluster_interconnect
PRIF-29: Warning: wildcard in network parameters can cause mismatch
among GPnP profile, OCR, and system
```
Note:

Legacy network configuration does not support wildcards; thus wildcards are resolved using current node configuration at the time of the update.

See Also:

Oracle Interface Configuration Tool (OIFCFG) Command Reference for more information about using OIFCFG commands
After the previous step completes, you can remove the former subnet, as follows, by providing the name and subnet address of the former interface:
```
oifcfg delif -global if_name/subnet
```
For example:
```
$ oifcfg delif -global eth1/10.10.0.0
```
Caution:

This step should be performed only after a replacement interface is committed into the Grid Plug and Play configuration. Simple deletion of cluster interfaces without providing a valid replacement can result in invalid cluster configuration.

Verify the current configuration using the following command:

oifcfg getif

For example:

$ oifcfg getif
eth2 10.220.52.0 global cluster_interconnect
eth0 10.220.16.0 global public

Stop Oracle Clusterware on all nodes by running the following command as root on each node:
```
# crsctl stop crs
```
Note:

With cluster network configuration changes, the cluster must be fully stopped; do not use rolling stops and restarts.
When Oracle Clusterware stops, you can deconfigure the deleted network interface in the operating system using the ifconfig command. For example:
```
$ ifconfig down
```
At this point, the IP address from network interfaces for the old subnet is deconfigured from Oracle Clusterware. This command does not affect the configuration of the IP address on the operating system.

You must update the operating system configuration changes, because changes made using ifconfig are not persistent.
Restart Oracle Clusterware by running the following command on each node in the cluster as the root user:
```
# crsctl start crs
```
The changes take effect when Oracle Clusterware restarts.

If you use the CLUSTER_INTERCONNECTS initialization parameter, then you must update it to reflect the changes.