Barracuda Networks Load Balancer, Руководство администратора

Страница: 23 / 76

Load Balancing Concepts 23
through their own interfaces. This implementation requires enabling a non-ARPing loopback adapter,
a feature that can be found on most server operating systems. Your applications may need to be
explicitly bound to the loopback adapter.
The Barracuda Load Balancer does not alter packets when it delivers them to the Real Servers.
Instead, only the destination MAC address is changed to match the Real Server that is to handle the
request, as shown in
Figure 2.5 .
Figure 2.5: Direct Server Return Packet Handling
DSR configuration can be more complex than the other methods of deployment. Because of this, it
is recommended that it be used only when there is a specific need. Situations where DSR is
recommended include streaming media, Real Servers not on an isolated subnet, and Windows servers.
• If the outbound traffic is far greater than the inbound traffic, for example, if the Real
Servers are providing streamed audio or visual media, throughput will be increased by
using DSR.
• If the Real Servers cannot be placed on a separate and isolated subnet from the Barracuda
Load Balancer, it may be better to use DSR than Route-Path. If the Real Servers are in a