Installation guide

Chapter 9. Setting Up a Red Hat Enterprise Linux LVS Cluster 107

Important

The adapter devices on the LVS routers must be conﬁgured to access the same networks.

For instance if eth0 connects to public network and eth1 connects to the private network,

then these same devices on the backup LVS router must connect to the same networks.

Also the gateway listed in the ﬁrst interface to come up at boot time is added to the routing

table and subsequent gateways listed in other interfaces are ignored. This is especially

important to consider when conﬁguring the real servers.

After physically connecting together the cluster hardware, conﬁgure the network inter-

faces on the primary and backup LVS routers. This can be done using a graphical ap-

plication such as system-conﬁg-network or by editing the network scripts manually. For

more information about adding devices using system-conﬁg-network, see the chapter ti-

tled Network Conﬁguration in the Red Hat Enterprise Linux System Administration Guide.

For more information on editing network scripts by hand, see the chapter titled Network

Scripts in the Red Hat Enterprise Linux Reference Guide. For the remainder of the chapter,

example alterations to network interfaces are made either manually or through the Piranha

Conﬁguration Tool.

9.2.1. General LVS Networking Tips

Conﬁgure the real IP addresses for both the public and private networks on the LVS routers

before attempting to conﬁgure the cluster using the Piranha Conﬁguration Tool. The

sections on each topography give example network addresses, but the actual network ad-

dresses are needed. Below are some useful commands for bringing up network interfaces

or checking their status.

Bringing Up Real Network Interfaces

The best way to bring up any real network interface is to use the following commands

as root replacing N with the number corresponding to the interface (eth0 and eth1):

/sbin/ifup ethN

Warning

Do not use the ifup scripts to bring up any ﬂoating IP addresses you may conﬁgure

using Piranha Conﬁguration Tool (eth0:1 or eth1:1). Use the service command

to start pulse instead (see Section 10.8 Starting the Cluster for details).

To bring a network interface down, type the following command:

/sbin/ifdown ethN

Again, replace N in the above command with the number corresponding to the inter-

face you wish to bring down.