Section 8.2:Configuring Network Interfaces for a NAT LVS Cluster
125
Note
Once the network interfaces are up on the real servers, the machines will
be unable to ping or connect in other ways to the public network. This is
normal. You will, however, be able to ping the real IP for the LVS router’s
private interface, in this case 10.11.12.8.
So the real server’s
/etc/sysconfig/network-scripts/ifcfg-eth0
file could look sim-
ilar 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 clus-
tering, 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/syscon-
fig/network-scripts/
directory or by making sure the gateway
is correctly set in the interface which comes up first.
8.2.2 Enabling NAT Routing on the LVS Routers
In a simple NAT LVS cluster 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 Section 7.5, Turning on 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 Section 8.3, Multi-port Services
and LVS Clustering.
Summary of Contents for ENTERPRISE LINUX AS 2.1 -
Page 1: ...Red Hat Enterprise Linux AS 2 1 The Official Red Hat Enterprise Linux AS Installation Guide ...
Page 8: ...viii ...
Page 14: ...xiv Introduction ...
Page 15: ...Part I Installing Red Hat Enterprise Linux AS ...
Page 16: ......
Page 26: ...26 Chapter 1 Steps to Get You Started ...
Page 30: ...30 Chapter 2 System Requirements Table ...
Page 80: ...80 Chapter 3 Installing Red Hat Enterprise Linux AS ...
Page 94: ...94 Chapter 4 Installing Red Hat Enterprise Linux AS via Text Mode ...
Page 95: ...Part II Configuring Red Hat Enterprise Linux AS ...
Page 96: ......
Page 100: ...100 Chapter 5 Introduction ...
Page 114: ...114 Chapter 6 Linux Virtual Server Overview ...
Page 153: ...Part III Appendixes ...
Page 154: ......
Page 156: ...156 Appendix A Additional Resources for LVS Clustering ...
Page 160: ...160 Appendix B A Sample etc sysconfig ha lvs cf File ...
Page 162: ...162 Appendix C Removing Red Hat Linux ...
Page 168: ...168 Appendix D Getting Technical Support ...
Page 178: ...178 Appendix E Troubleshooting Your Installation of Red Hat Enterprise Linux AS ...