Lvs Via Direct Routing - Red Hat LINUX VIRTUAL SERVER - FOR ENTERPRISE LINUX 5.2 REV 05-2008 Manual

Chapter 3. Setting Up LVS
firewall marks, see Section 4, "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
Chapter 4, Configuring the LVS Routers with Piranha Configuration
Warning
Do not configure the floating IP for
network scripts or using a network configuration tool. Instead, use the Piranha
Configuration Tool as shown in
Section 6.1, "The VIRTUAL SERVER
When finished, start the
and running, the active LVS router will begin routing requests to the pool of real servers.

2. LVS via Direct Routing

As mentioned in Section 4.2, "Direct
route packets directly to a requesting user rather than passing outgoing packets through the
LVS router. Direct routing requires that the real servers be physically connected to a network
segment with the LVS router and be able to process and direct outgoing packets as well.
Network Layout
In a direct routing LVS setup, the LVS router needs to receive incoming requests and route
them to the proper real server for processing. The real servers then need to directly route
the response to the client. So, for example, if the client is on the Internet, and sends the
packet through the LVS router to a real server, the real server must be able to go directly to
the client via the Internet. This can be done by configuring a gateway for the real server to
pass packets to the Internet. Each real server in the server pool can have its own separate
gateway (and each gateway with its own connection to the Internet), allowing for maximum
throughput and scalability. For typical LVS setups, however, the real servers can
communicate through one gateway (and therefore one network connection).
Important
It is not recommended to use the LVS router as a gateway for the real servers,
as that adds unneeded setup complexity as well as network load on the LVS
router, which reintroduces the network bottleneck that exists in NAT routing.
Hardware
The hardware requirements of an LVS system using direct routing is similar to other LVS
topologies. While the LVS router needs to be running Red Hat Enterprise Linux to process
26
service as shown in
pulse
Routing", direct routing allows real servers to process and
LVS".
Tool.
or by manually editing
eth0:1 eth1:1
Section 4, "GLOBAL SETTINGS"
Subsection".
Section 8, "Starting
and
LVS". Once is up
pulse