As discussed with Jr. DBA there were “Global Cache Blocks Lost wait event” observed in RAC Database
We also notified that network packet dropped on interface level whenever server reboot issues faced .
I came to know one good Oracle RAC Recommendations for Private Network NIC Configuration
Flow control: control is the process of managing the rate of data transmission between two nodes to prevent a fast sender from outrunning a slow receiver. It provides a mechanism for the receiver to control the transmission speed, so that the receiving node is not overwhelmed with data from sending nodes. Flow control should be distinguished from congestion control. Oracle recommends that for the flow control Rx=on tx=off
You can check RX and TX using below command
ethtool -a eth1
For private connections ORACLE recommends the RX flow control to be on and TX to be off. So I made the changes.
ethtool -A eth1 rx on tx off autoneg on
However the changes are lost when the server reboots. So I added the command to /etc/rc.local file to make the changes persistent.
As a result the network card settings for the private connection should be:
full duplex, autoneg on, rx on , tx off