Turning on Packet Forwarding

In order for the LVS router to forward network packets properly to the real servers, each LVS router node must have IP forwarding turned on in the kernel. Log in as root and change the line which reads net.ipv4.ip_forward = 0 in /etc/sysctl.conf to the following:

net.ipv4.ip_forward = 1

The changes will take effect when you reboot the system.


If this is the first time booting into Red Hat Enterprise Linux AS, you will also need to manually turn on forwarding by issuing the following command as root:

echo 1 > /proc/sys/net/ipv4/ip_forward

To check the status of IP forwarding at any time, issue the following command:

cat /proc/sys/net/ipv4/ip_forward

If the above command returns a 1, IP forwarding is enabled. If it returns a 0, then you must issue the echo command listed above.