Install guide

WAN Load Balancing 1-9
Software Version 2.7.5
C613-10454-00 REV A
To determine a host's reachability, the router sends it a series of healthcheck
packets. After it receives a set number of successful responses termed
successchecks, it considers the host to be reachable. If the router has received no
replies to a defined number of healthcheck requests called failchecks, it
considers the host to be unreachable.
You can configure the various healthcheck parameters by using the set wanlb
healthcheck command on page 1-32.
Operation with Other Software Features
This section describes how the load balancer can be used with other software
features within the router.
Operation with Firewall
It is not necessary to configure the router as a firewall in order to apply WAN
load balancing, although the two features have been designed to operate
together and the load balancing operation will operate more effectively when
used with a firewall running network address translation (NAT). The diagram
shown in Figure 1-1 shows the relationship between the load balancer and the
firewall functions within the router.
Figure 1-1: Example load balancer operation with firewall
WAN ISP1
IP Flow IP Flow IP Flow
Private Side
Firewall
with
NAT
WAN ISP2
WANLB-fw1.eps
WAN Load Balancer
IP Module
Router
NATx
NATy