Tuning the Cluster Interconnect - Expert Oracle RAC Performance Diagnostics and Tuning - page 454

eth20 and eth21 are the physical public interfaces; however, they are bonded/paired
together ( bond0 ).
eth24 and eth25 are the physical private interfaces; however, they are bonded/paired
together ( bond2 ).
lo0 : in the output also indicates that there is a loopback option configured. Verification of
whether Oracle is using the loopback option should also be verified using the ORADEBUG
command and is discussed later in this section. The use of the loopback IP depends on the
integrity of the routing table defined on each of the nodes. Modification of the routing table
can result in the inoperability of the interconnect.

In the previous netstat output, there are two types of NIC configurations. The public NIC has an MTU set at
1,500 bytes, but the private NIC has an MTU set to 9,000 bytes.

■ Note in the previous output, niC pairing/bonding is used for both public ( bond0 ) and private ( bond2 ) networks.

Check 3
The database and ASM alert logs show entries related to the interconnect.
Both the RDBMS and ASM alert logs can also be sources to confirm this information:

Starting ORACLE instance (normal)
LICENSE_MAX_SESSION = 0
LICENSE_SESSIONS_WARNING = 0
Private Interface 'eth22:1' configured from GPnP for use as a private interconnect.
[name='eth22:1', type=1, ip=169.254.62.94, mac=00-23-7d-36-5b-90, net=169.254.0.0/18,
mask=255.255.192.0, use=haip:cluster_interconnect/62]

After instance is started, Oracle then provides the IP addresses configured for the interconnect also in the
alert log files:

Cluster communication is configured to use the following interface(s) for this instance
169.254.62.94
169.254.122.73
169.254.155.149
169.254.238.3
cluster interconnect IPC version:Oracle UDP/IP (generic)
IPC Vendor 1 proto 2

Check 4
The next important check would be to determine the transfer rate vs. the actual implemented packet size to ensure
the installation has been carried out per specification.