**Oracle Grid Infrastructure** requires 2 network interfaces:

  * Public
  * Private


The public interface should host the following IPs: 
  - Public Host IP
  - Node VIP
  - SCAN VIP
  - APP VIP
  - GNS VIP
  - and Others

While the Private interface hosts only 1 IP, BUT it there can be many private interfaces grouped under HAIP


The following configuration can be used for: Public Interface: eth0
<sxh>
[root@lparacb ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 
DEVICE=eth0
HWADDR=08:00:27:70:D3:B7
TYPE=Ethernet
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.100.20
NETMASK=255.255.255.0
PEERDNS=no
[root@lparacb ~]# 
</sxh>


The following configuration can be used for: Private Interface: eth1
<sxh>
[root@lparacb ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth1 
DEVICE=eth1
HWADDR=08:00:27:C5:75:A7
TYPE=Ethernet
ONBOOT=yes
BOOTPROTO=static
IPADDR=10.0.2.20
NETMASK=255.255.255.0
PEERDNS=no
[root@lparacb ~]# 
</sxh>

**PEERDNS is important otherwise you will inherit the DNS from the base system**