Change Cluster Interconnect Adapter IP Address in 11gR2 RAC

Cluster interconnect: It’s a private interface used for the cluster-ware to provide inter-instance or
Cache Fusion communication. This is also called as private IP address.

Step 1: Determine private IP address and Ethernet card name

[oracle@rac1 ~]$ oifcfg getif
eth0  147.43.0.0  global  public
eth1  192.168.0.0  global  cluster_interconnect

Step 2: Add new interface Subnet ID specification:

[oracle@rac1 ~]$ oifcfg setif -global eth1/172.16.0.0:cluster_interconnect

Step 3 : Verify the changes:

[oracle@rac1 ~]$ oifcfg getif
eth0  147.43.0.0  global  public
eth1  192.168.0.0  global  cluster_interconnect
eth1  172.16.0.0  global  cluster_interconnect

Step 4: Stop cluster on all node:

[root@rac1 ~]# crsctl stop cluster -all

Step 5: Modify netwrok address on network adapter of each box:

[root@rac1 ~]# ifconfig eth1 172.16.0.10 netmask 255.255.0.0 broadcast 172.16.255.255

[root@rac2 ~]# ifconfig eth1 172.16.0.11 netmask 255.255.0.0 broadcast 172.16.255.255

Step 6: Modify /etc/hosts file on each node.

Delete entry of old private interconnect and add new private interconnect on each node.

[root@rac1 ~]# cat /etc/hosts

#Private

172.16.0.10         rac1-priv.pavan.com        rac1-priv

172.16.0.11         rac2-priv.pavan.com        rac2-priv

Step 7: Start cluster on each node

[root@rac1 ~]# crsctl start cluster -all

Step 8: Delete old entry of private interconnect from cluster registry

[root@rac1 ~]# oifcfg delif -global eth1/192.168.0.0:cluster_interconnect

Step 9: Verify the changes:

[root@rac1 ~]# oifcfg getif

eth0  147.43.0.0  global  public

eth1  172.16.0.0  global  cluster_interconnect

You can also verify:

[root@rac1 ~]# ifconfig eth1

eth1      Link encap:Ethernet  HWaddr 00:0C:29:1F:C8:9B  

          inet addr:172.16.0.10  Bcast:172.16.255.255  Mask:255.255.0.0

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:233241 errors:0 dropped:0 overruns:0 frame:0

          TX packets:191677 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:131223995 (125.1 MiB)  TX bytes:91090699 (86.8 MiB)

[root@rac1 ~]# ping rac2-priv

PING rac2-priv.pavan.com (172.16.0.11) 56(84) bytes of data.

64 bytes from rac2-priv.pavan.com (172.16.0.11): icmp_seq=1 ttl=64 time=0.263 ms

64 bytes from rac2-priv.pavan.com (172.16.0.11): icmp_seq=2 ttl=64 time=0.230 ms

^C

--- rac2-priv.pavan.com ping statistics ---

2 packets transmitted, 2 received, 0% packet loss, time 999ms

rtt min/avg/max/mdev = 0.230/0.246/0.263/0.022 ms