Enabling Nat Routing On The Lvs Routers; Lvs Via Direct Routing - Red Hat ENTERPRISE LINUX 5 - VIRTUAL SERVER ADMINISTRATION Manual

So the real server's /etc/sysconfig/network-scripts/ifcfg-eth0 file could look similar to
this:
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=10.11.12.1
NETMASK=255.255.255.0
GATEWAY=10.11.12.10
Warning
If a real server has more than one network interface configured with a GATEWAY= line, the
first one to come up will get the gateway. Therefore if both eth0 and eth1 are configured
and eth1 is used for LVS, the real servers may not route requests properly.
It is best to turn off extraneous network interfaces by setting ONBOOT=no in their network
scripts within the /etc/sysconfig/network-scripts/ directory or by making sure
the gateway is correctly set in the interface which comes up first.

3.1.3. Enabling NAT Routing on the LVS Routers

In a simple NAT LVS configuration where each clustered service uses only one port, like HTTP on
port 80, the administrator needs only to enable packet forwarding on the LVS routers for the requests
to be properly routed between the outside world and the real servers. See
Packet Forwarding"
for instructions on turning on packet forwarding. However, more configuration is
necessary when the clustered services require more than one port to go to the same real server during
a user session. For information on creating multi-port services using firewall marks, see
"Multi-port Services and
Once forwarding is enabled on the LVS routers and the real servers are set up and have the clustered
services running, use the Piranha Configuration Tool to configure LVS as shown in
Configuring the LVS Routers with Piranha Configuration
Warning
Do not configure the floating IP for eth0:1 or eth1:1 by manually editing network scripts
or using a network configuration tool. Instead, use the Piranha Configuration Tool as
Section 4.4, "GLOBAL SETTINGS"
shown in
Subsection".
When finished, start the pulse service as shown in
and running, the active LVS router will begin routing requests to the pool of real servers.

3.2. LVS via Direct Routing

Section 1.4.2, "Direct
As mentioned in
packets directly to a requesting user rather than passing outgoing packets through the LVS router.
LVS".
Routing", direct routing allows real servers to process and route
Enabling NAT Routing on the LVS Routers
Section 2.5, "Turning on
Tool.
Section 4.6.1, "The VIRTUAL SERVER
and
Section 4.8, "Starting LVS". Once pulse is up
Section 3.4,
Chapter 4,
21