Turning On Packet Forwarding - Red Hat ENTERPRISE LINUX AS 2.1 Installation Manual

Section 7.5:Turning on Packet Forwarding
You can also allow specific hosts or subnets as in this example:
Order deny,allow
Deny from all
Allow from 192.168.1.100
Allow from 172.16.57
In the above example, only Web browsers from the machine with the IP address of 192.168.1.100 and
machines on the 172.16.57/24 network can access the Piranha Configuration Tool.
Editing this file limits access to the configuration pages in /etc/syscon-
fig/ha/web/secure/ directory but not to the login and the help pages
in /etc/sysconfig/ha/web/. To limit access to this directory, create
a .htaccess file in the /etc/sysconfig/ha/web/ with order,
allow, and deny lines identical to /etc/sysconfig/ha/web/se-
cure/.htaccess.

7.5 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:
echo 1 > cat /proc/sys/net/ipv4/ip_forward
To turn on IP forwarding manually, issue the following command as root:
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.
CAUTION
Tip
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