Red Hat CLUSTER SUITE FOR ENTERPRISE LINUX 4.5 Overview page 45

Routing Methods
Figure 1.24. LVS Implemented with Direct Routing
In a typical direct-routing LVS configuration, an LVS router receives incoming server requests
through a virtual IP (VIP) and uses a scheduling algorithm to route the request to real servers.
Each real server processes requests and sends responses directly to clients, bypassing the
LVS routers. Direct routing allows for scalability in that real servers can be added without the
added burden on the LVS router to route outgoing packets from the real server to the client,
which can become a bottleneck under heavy network load.
While there are many advantages to using direct routing in LVS, there are limitations. The most
common issue with direct routing and LVS is with Address Resolution Protocol (ARP).
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