17.5 Installing and Configuring Keepalived

The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

17.5 Installing and Configuring Keepalived

17.5.1 About the Keepalived Configuration File

To install Keepalived:

Install the keepalived package on each server:
```
# yum install keepalived
```
Edit /etc/keepalived/keepalived.conf to configure Keepalived on each server. See Section 17.5.1, “About the Keepalived Configuration File”.

Enable IP forwarding:

# echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf
# sysctl -p
net.ipv4.ip_forward = 1

Add firewall rules to allow VRRP communication using the multicast IP address 224.0.0.18 and the VRRP protocol (112) on each network interface that Keepalived will control, for example:
```
# iptables -I INPUT -i eth0 -d 224.0.0.0/8 -p vrrp -j ACCEPT
# iptables -I OUTPUT -o eth0 -d 224.0.0.0/8 -p vrrp -j ACCEPT
# service iptables save
```
Enable and start the keepalived service on each server:
```
# chkconfig keepalived on
# service keepalived start
```
If you change the Keepalived configuration, reload the keepalived service:
```
# service keepalived reload
```